程序代码：

Dim s As String
Dim i As Long
Dim s2() As Byte

s = InputBox("请输入密文：", "密文")
s2 = StrConv(s, vbFromUnicode)          '转BYTE数组
For i = 0 To UBound(s2)            '处理过程抄 lowxiong 的 C 代码
    Select Case s2(i)
        Case 48
            s2(i) = 32
        Case 49 To 57
            s2(i) = s2(i) + 16
        Case 65 To 81
            s2(i) = s2(i) + 41
        Case 82 To 90
            s2(i) = s2(i) + 15
        End Select
Next i
MsgBox StrConv(s2, vbUnicode)