Private Function ConvertColumnNumberToLetter(ByVal ColumnNumber As Integer)
IntegerResult = ColumnNumber \ 26
FractionalResult = (ColumnNumber / 26) - IntegerResult
Remainder = ColumnNumber Mod 26
If IntegerResult = 0 Then
    FirstLetter = ""
ElseIf IntegerResult = 1 And FractionalResult = 0 Then
    FirstLetter = ""
    ConvertColumnNumberToLetter = "Z"
    Exit Function
ElseIf IntegerResult > 1 And FractionalResult = 0 Then
    FirstLetter = Chr(64 + (IntegerResult - 1))
    ConvertColumnNumberToLetter = FirstLetter & "Z"
    Exit Function
Else
    FirstLetter = Chr(64 + IntegerResult)
End If
SecondLetter = Chr(64 + Remainder)
ConvertColumnNumberToLetter = FirstLetter & SecondLetter
End Function