How do I get regex support in excel via a function, or custom function?

Question

It appears that regex (as in regular expressions) is not supported in excel, except via VBA. Is this so, and if it is, are there any \"open source\" custom VBA functions tha

Answer 1

I recently had the same exact question and after struggling with creating my own tools and making them work correctly I found a great online ADDIN that's very EASY to USE.

This is the creator's excerpt

For my internship over the past several months I’ve been working in the Marketing Science department and part of my job has been getting data into MS Access and generating reports. This involves getting lists of prospects from various data sources. This was usually a pretty simple feat involving some basic SQL queries. However, sometimes I was handed data such as addresses that didn’t match any standard format used by IT. In the worst case the data was provided in a pdf which meant I could only export it to a non-delimited text file. I found that I really needed a couple generic regular expression functions to parse out fields to import into MS Access. I found some .xla examples online but I really wanted an easier to use, more extensive, and portable library. I also wanted to include a few basic patterns for so it wasn’t necessary to re-invent the wheel every time.

So, I created a simple Excel Add-In Regular Expressions.xla that adds several custom functions to implement the standard VBScript regular expressions.

Here is the website

I've used it successfully to extract useful text using regex.

Here's the code in the addin

' Regular Expressions.xla
'
' ? 2010 Malcolm Poindexter
' This is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License
' as published by the Free Software Foundation, version 3.
' This software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
' without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
' See the GNU General Public License for more details. http://www.gnu.org/licenses/gpl.html
'
' I would appreciate if you would notify me of any modifications or re-distributions of this code at contact@malcolmp.com
' and appropriately attribute me as the original author in the header.
' ------------------------------------------------------------------------------------------------------------------------
'
' This file provides an Excel Add-In containing regular expression processing functions and several pre-defined regular expressions.
' The regular expressions provided are not necessarially exhaustive, but are intended to cover the most common cases.
'
' Regular Expressions Syntax: http://msdn.microsoft.com/en-us/library/1400241x%28VS.85%29.aspx

' -----------------------------
' NAME: xREPLACE
' DESCRIPTION: Replace all portions of the search text matching the pattern with the replacement text.
' -----------------------------
Function xREPLACE(pattern As String, searchText As String, replacementText As String, Optional ignoreCase As Boolean = True) As String
    On Error Resume Next
    Dim RegEx As New RegExp
    RegEx.Global = True
    RegEx.MultiLine = True
    RegEx.pattern = pattern
    RegEx.ignoreCase = ignoreCase
    xREPLACE = RegEx.Replace(searchText, replacementText)
End Function

' -----------------------------
' NAME: xMATCHES
' DESCRIPTION: Find and return the number of matches to a pattern in the search text.
' -----------------------------
Function xMATCHES(pattern As String, searchText As String, Optional ignoreCase As Boolean = True) As String
    On Error Resume Next
    Dim RegEx As New RegExp
    RegEx.Global = True
    RegEx.MultiLine = True
    RegEx.pattern = pattern
    RegEx.ignoreCase = ignoreCase
    Dim matches As MatchCollection
    Set matches = RegEx.Execute(searchText)
    xMATCHES = matches.Count
End Function

' -----------------------------
' NAME: xMATCH
' DESCRIPTION: Find and return an instance of a match to the pattern in the search text. MatchIndex may be used in the case of multiple matches.
' -----------------------------
Function xMATCH(pattern As String, searchText As String, Optional matchIndex As Integer = 1, _
                Optional ignoreCase As Boolean = True) As String
    On Error Resume Next
    Dim RegEx As New RegExp
    RegEx.Global = True
    RegEx.MultiLine = True
    RegEx.pattern = pattern
    RegEx.ignoreCase = ignoreCase
    Dim matches As MatchCollection
    Set matches = RegEx.Execute(searchText)
    Dim i As Integer
    i = 1
    For Each Match In matches
        If i = matchIndex Then
            xMATCH = Match.Value
        End If
        i = i + 1
    Next
End Function

' -----------------------------
' NAME: xMATCHALL
' DESCRIPTION: Find and return a comma-separated list of all matches to the pattern in the search text.
' -----------------------------
Function xMATCHALL(pattern As String, searchText As String, Optional ignoreCase As Boolean = True) As String
    On Error Resume Next
    Dim RegEx As New RegExp
    RegEx.Global = True
    RegEx.MultiLine = True
    RegEx.pattern = pattern
    RegEx.ignoreCase = ignoreCase
    Dim matches As MatchCollection
    Set matches = RegEx.Execute(searchText)
    Dim i As Integer
    i = 1
    Dim returnMatches As String
    returnMatches = ""
    For Each Match In matches
        If i = 1 Then
            returnMatches = Match.Value
        Else
            returnMatches = returnMatches + "," + Match.Value
        End If
        i = i + 1
    Next
    xMATCHALL = returnMatches
End Function

' -----------------------------
' NAME: xGROUP
' DESCRIPTION: Find and return a group from within a matched pattern.
' -----------------------------
Function xGROUP(pattern As String, searchText As String, group As Integer, Optional matchIndex As Integer = 1, _
                Optional ignoreCase As Boolean = True) As String
    On Error Resume Next
    If group <> 0 Then
        group = group - 1
    End If
    Dim RegEx As New RegExp
    RegEx.Global = True
    RegEx.MultiLine = True
    RegEx.pattern = pattern
    RegEx.ignoreCase = ignoreCase
    Dim matches As MatchCollection
    Set matches = RegEx.Execute(searchText)
    Dim i As Integer
    i = 1
    For Each Match In matches
        If i = matchIndex Then
            xGROUP = Match.SubMatches(group)
        End If
        i = i + 1
    Next
End Function

' -----------------------------
' NAME: xSTARTSWITH
' DESCRIPTION: Returns true or false if the search text starts with the pattern.
' -----------------------------
Function xSTARTSWITH(pattern As String, searchText As String, Optional ignoreCase As Boolean = True) As String
    On Error Resume Next
    Dim RegEx As New RegExp
    RegEx.Global = True
    RegEx.MultiLine = True
    RegEx.pattern = "^" + pattern
    RegEx.ignoreCase = ignoreCase
    Dim matches As MatchCollection
    Set matches = RegEx.Execute(searchText)
    xSTARTSWITH = matches.Count > 0
End Function

' -----------------------------
' NAME: xENDSWITH
' DESCRIPTION: Returns true or false if the search text ends with the pattern.
' -----------------------------
Function xENDSWITH(pattern As String, searchText As String, Optional ignoreCase As Boolean = True) As String
    On Error Resume Next
    Dim RegEx As New RegExp
    RegEx.Global = True
    RegEx.MultiLine = True
    RegEx.pattern = pattern + "$"
    RegEx.ignoreCase = ignoreCase
    Dim matches As MatchCollection
    Set matches = RegEx.Execute(searchText)
    xENDSWITH = matches.Count > 0
End Function

' ************************************
' Regular Expression Definitions
' ************************************

' -----------------------------
' NAME: xxEMAIL
' DESCRIPTION: Pattern to match an email address.
' -----------------------------
Function xxEMAIL() As String
    xxEMAIL = "\b[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b"
End Function

' -----------------------------
' NAME: xxUSZIP
' DESCRIPTION: Pattern to match an US Zip code.
' -----------------------------
Function xxUSZIP() As String
    xxUSZIP = "\b(?!0{5})(\d{5})(?!-0{4})(-\d{4})?\b"
End Function

' -----------------------------
' NAME: xxPHONE
' DESCRIPTION: Pattern to match a phone number.
' -----------------------------
Function xxPHONE() As String
    xxPHONE = "\b[01]?[- .]?\(?[2-9]\d{2}\)?\s?[- .]?\s?\d{3}\s?[- .]?\s?\d{4}(\s*(x|(ext))[\.]?\s*\d{1,6})?\b"
End Function

' -----------------------------
' NAME: xxURL
' DESCRIPTION: Pattern to match a url.
' -----------------------------
Function xxURL() As String
    xxURL = "\b((ftp)|(https?))\://[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}\b"
End Function


' ************************************
'   Insert Function Dialog Category Setup
' ************************************
Sub AddCategoryDescription()
    Application.MacroOptions Macro:="xREPLACE", _
        Description:="Replace all portions of the search text matching the pattern with the replacement text.", _
        Category:="Regular Expressions"

    Application.MacroOptions Macro:="xMATCHES", _
        Description:="Find and return the number of matches to a pattern in the search text.", _
        Category:="Regular Expressions"

    Application.MacroOptions Macro:="xMATCH", _
        Description:="Find and return an instance of a match to the pattern in the search text. MatchIndex may be used in the case of multiple matches.", _
        Category:="Regular Expressions"

    Application.MacroOptions Macro:="xMATCHALL", _
        Description:="Find and return a comma-separated list of all matches to the pattern in the search text.", _
        Category:="Regular Expressions"

    Application.MacroOptions Macro:="xGROUP", _
        Description:="Find and return a group from within a matched pattern.", _
        Category:="Regular Expressions"

    Application.MacroOptions Macro:="xSTARTSWITH", _
        Description:="Returns true or false if the search text starts with the pattern.", _
        Category:="Regular Expressions"

    Application.MacroOptions Macro:="xENDSWITH", _
        Description:="Returns true or false if the search text ends with the pattern.", _
        Category:="Regular Expressions"

    '**** Regular Expressions ****

    Application.MacroOptions Macro:="xxEMAIL", _
        Description:="Pattern to match an email address.", _
        Category:="Regular Expressions"

    Application.MacroOptions Macro:="xxUSZIP", _
        Description:="Pattern to match an US Zip code.", _
        Category:="Regular Expressions"

    Application.MacroOptions Macro:="xxPHONE", _
        Description:="Pattern to match a phone number.", _
        Category:="Regular Expressions"

    Application.MacroOptions Macro:="xxURL", _
        Description:="Pattern to match a url.", _
        Category:="Regular Expressions"
End Sub