How to change case of matching letter with a VBA regex Replace?

Question

I have a column of lists of codes like the following.

2.A.B, 1.C.D, A.21.C.D, 1.C.D.11.C.D
6.A.A.5.F.A, 2.B.C.H.1
8.ABC.         


        

Answer 1

Here is a workaround that uses the properties of each individual regex match to make the VBA Replace() function replace only the text from the match and nothing else.

Sub fixBlah2()
Dim re As VBScript_RegExp_55.RegExp, Matches As VBScript_RegExp_55.MatchCollection
Dim M As VBScript_RegExp_55.Match
Dim tmpChr As String, pre As String, i As Integer
Set re = New VBScript_RegExp_55.RegExp
re.Global = True
re.Pattern = "\b([1-5]\.[A-Z])\.([A-Z])\b"
For Each c In Selection.Cells
    'Count of number of replacements made. This is used to adjust M.FirstIndex
    '    so that it still matches correct substring even after substitutions.
    i = 0
    Set Matches = re.Execute(c.Value)
    For Each M In Matches
        tmpChr = LCase(M.SubMatches.Item(1))
        If M.FirstIndex > 0 Then
            pre = Left(c.Value, M.FirstIndex - i)
        Else
            pre = ""
        End If
        c.Value = pre & Replace(c.Value, M.Value, M.SubMatches.Item(0) & tmpChr, _ 
                  M.FirstIndex + 1 - i, 1)
        i = i + 1
    Next M
Next c
End Sub

For reasons I don't quite understand, if you specify a start index in Replace(), the output starts at that index as well, so the pre variable is used to capture the first part of the string that gets clipped off by the Replace function.