用vba代码：把“a5：a100 ”里15位的身份证号转换为18位

=IDCODE(a1)  （假设A1单元格存放的是原15位号码）（自定义函数）
Public Function IDCode(sCode15 As String) As String
    Dim i, num As Integer
    Dim code As String
    num = 0
    IDCode = Left(sCode15, 6) + "19" + Right(sCode15, 9)
    '　计算校验位
    For i = 18 To 2 Step -1
      num = num + (2 ^ (i - 1) Mod 11) * (Mid(IDCode, 19 - i, 1))
    Next i
    num = num Mod 11
    Select Case num
    Case 0
      code = "1"
    Case 1
      code = "0"
    Case 2
      code = "X"
    Case Else
      code = Trim(Str(12 - num))
    End Select
    IDCode = IDCode + code
End Function