How to ovverride Copy command on WPF textbox?

Question

Hello,

I would like to override the behavior of RoutedUICommand "Copy" of a WPF TextBox.

Is it possible without creating a new TextBoxExtended class that inherits from TextBox?

I have reached that point, but now I am bit lost.

Private Sub tbSource_PreviewExecuted(ByVal sender As System.Object, ByVal e As System.Windows.Input.ExecutedRoutedEventArgs)

        Dim commandName = DirectCast(e.Command, Input.RoutedUICommand).Text

        If commandName = "Copy" Then

        End If

End Sub

Do you have any idea how to continue?