VBA列号和数字转换

Function StrToNum(ByVal Str As String) As Long '字母转数字
    Dim s As String, S1 As String
    If Str = "" Then Exit Function
    Str = UCase(Str)
    s = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    For i = 1 To Len(Str)
        S1 = Mid(Str, i, 1)
        If InStr(s, S1) = 0 Then Crazy_Num = -1: Exit Function
        StrToNum = StrToNum + InStr(s, S1) * 26 ^ (Len(Str) - i)
    Next
End Function

Function NumToStr(ByVal Num As Long) As String   '数字转字母
    Dim M As Long
    If Num < 1 Then Exit Function
    Do
        M = Num Mod 26
        If M = 0 Then M = 26
        NumToStr = Chr(64 + M) & NumToStr
        Num = (Num - M) / 26
    Loop Until Num <= 0
End Function