You could add an MDN to a digital handset key and apply then divert from there.
You could also use Personal Number (PELPI).
[red]Striker : My orders came through. My squadron ships out tomorrow, we're bombing the storage depots at Daiquiri at 18:00 hours. We're coming in from the North, below their radar.[/red]
[blue]Elaine : When will you be back?[/blue]
[red]Striker : I can't tell you that? It's classified.[/red]