VB.net TextField - limit numbers but allow Ctrl+C, Ctrl+V and Ctrl+X

Hi
I've got many textfields which are limited to numbers being entered with the following in the KeyPress handler (got this code from internet)

            Dim KeyAscii As Short = Asc(e.KeyChar)
            Select Case KeyAscii
                Case System.Windows.Forms.Keys.Back  '<--- this is for  backspace
                Case 46 'System.Windows.Forms.Keys.Decimal '<--- this is for  point key
                    'no decimals already and not first decimal
                    If sender.Text.IndexOf(".") = -1 And sender.Text.Length > 0 Or sender.selectionstart = 0 Then
                        Exit Sub
                    Else
                        e.Handled = True
                        TestForm.IsChangesMade = True
                        Exit Sub
                    End If
                Case 48 To 57     '<--- this is for numbers
                    Exit Sub
                Case 45     '<-- for negatives, allow at first position and only 1 negative
                    If sender.Text.IndexOf("-") = -1 And sender.Text.Length > 0 Then
                        Exit Sub
                    Else
                        e.Handled = True
                        Exit Sub
                    End If
                Case Else 'cancel key entry
                    e.Handled = True
            End Select


This works fine. However it means that keyboard shortcuts don't work.

Help please as I'd like the cut, copy and paste still to work.

Thanks in advance.Start Free Trial