Private Function Encrypt(ByVal tcString As String, ByVal tcKey As String) As String
        Dim lnLen As Long, lcKeyExpr As String, lcEncrypt As String, lnI As Long, lnChar As Byte
        lnLen = Len(tcString)
        lcKeyExpr = tcKey
        Do While Len(lcKeyExpr) < lnLen
            lcKeyExpr = lcKeyExpr & tcKey
        Loop
        lcEncrypt = ""
        For lnI = 1 To lnLen
            lnChar = Math.Min(Asc(Mid(tcString, lnI, 1)) + Asc(Mid(lcKeyExpr, lnI, 1)) + lnI, 255)
            lcEncrypt = lcEncrypt & Chr(lnChar)
        Next lnI
        Return lcEncrypt
    End Function