get column letter

[PMBottas]

Brute force approach...
try:

             Public Function GetColumnAddr(ByVal cellAddr As String, ByVal keepAbs As Boolean) As String
               Dim idx As Long
               Dim str As String
               Dim curChar As String
               
               If cellAddr = "" Then
                 GetColumnAddr = ""
                 Exit Function
               End If
               
               idx = 1
               str = "" ' not necessary but ...
     
               If Left(cellAddr, 1) = "$" Then 
               idx = 2
               if keepAbs then str = "$"
              End If
     
               curChar = Mid(cellAddr, idx, 1)
               While (Not IsNumeric(curChar)) And (curChar <> "$")
                 str = str & curChar
                 idx = idx + 1
                 curChar = Mid(cellAddr, idx, 1)
               Wend
               
               GetColumnAddr = str
               
             End Function