Any2Dec

Function Any2Dec(ByVal ConvertNumber As String, Optional ByVal base As Integer = 16) As Long
    Dim index As Long
    Dim digits As String
    Dim digitValue As Long
    Rett = ConvertNumber
    If base < 2 Or base > 36 Then Goto ByeBye ' Err.Raise 5 ' check base
    digits = Left("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ", base) ' get the list of valid digits
    For index = 1 To Len(ConvertNumber)    ' convert to decimal
        digitValue = InStr(1, digits, Mid$(ConvertNumber, index, 1), vbTextCompare) - 1 ' get the digit's value
        If digitValue < 0 Then Goto ByeBye ' Err.Raise 5 ' error if invalid digit
        Rett = Rett * base + digitValue ' add to running result
    Next
    ByeBye:
    Any2Dec = Rett
End Function