Restrict where?

This is code for a text box on a user form and allows specified ascii:

Private Sub TEXTBOXNAME_TextBox_KeyPress(ByVal KeyAscii As
MSForms.ReturnInteger)

   Select Case KeyAscii
       Case 48 To 57  ' 0 thru 9
       Case 65 To 90 '  A thru Z uppercase. 97 to 122 is lowercase
       Case Else
           KeyAscii = 0
   End Select

End Sub