Private Sub CommandButton1_Click()
Dim i As Byte, t As String, x As Integer
For i = 1 To Len(TextBox1)
x = Asc(Mid(TextBox1, i, 1))
If (x >= 88 And x <= 90) Or (x >= 120 And x <= 122) Then
x = x - 23
Else
x = x + 3
End If
t = t & Chr(x)
Next i
MsgBox t
End Sub