Dim mac As String, serial As String
Dim t As Integer, i As Integer
mac = "00 E0 4C DD 8A 69"
serial = ""
For i = 1 To Len(mac)
t = Asc(Mid(mac, i, 1)) '取得 ascii 码
t = t Xor 9 '以9来异或
.... '可加入更多数学运算
If t < 32 Then t = t + 32 '防止不可见字符出现
If t > 122 Then t = t - 122