原作:中国人, 咱家是猫 略作改动

Function AutoNum(strNum As String) As String
    AutoNum = StrReverse(Val(StrReverse(strNum & "1")))
    AutoNum = Left(AutoNum, Len(AutoNum) - 1)
    AutoNum = Left(strNum, Len(strNum) - Len(AutoNum)) & Format((AutoNum + 1), String(Len(AutoNum), "0"))
End Function