Public Function NextAlphaCode(ByVal code As String) As String
    'Developed by Marshall Barton MVP
    'Increments alphabetical codes
    Dim k As Integer
    
    For k = Len(code) To 1 Step -1
        If Mid(code, k, 1) < "Z" Then
            NextAlphaCode = left(code, k - 1) & _
                Chr(Asc(Mid(code, k, 1)) + 1) & Mid(code, k + 1)
            Exit Function
        Else
            code = left(code, k - 1) & "A" & Mid(code, k + 1)
        End If
    Next k
    
    NextAlphaCode = "A" & code
End Function