Convert excel column alphabet (e.g. AA) to number (e.g., 25)

Question

In my grid the column headers are named A,B,C...,AA,AB,AC,...etc like an excel spreadsheet. How can I convert the string to number like: A => 1, B =>

Answer 1

Public Function ColLet2Num(Letras As String)
'RALONSO MAYO 2017
'A-> 1
'OQ ->407
'XFD->16384
Dim UnChar As String
Dim NAsc As Long
Dim F As Long
Dim Acum As Long
Dim Indice As Long
Letras = UCase(Letras)
Acum = 0
Indice = 0
For F = Len(Letras) - 1 To 0 Step -1

    UnChar = Mid(Letras, F + 1, 1)
    NAsc = Asc(UnChar) - 64
    Acum = Acum + (NAsc * (26 ^ Indice))
    Indice = Indice + 1
Next
If Acum > 16384 Then
    MsgBox "La celda máxima es la XFD->16384", vbCritical
End If
ColLet2Num = Acum
End Function