[Asterisk-Users] Question setting up a "bat phone" extension.

[undrhil.1528785 at bloglines.com]

Basically, I am looking to set up an extension which will be used as a "help-line".
 I want it to function kind of like the bat phone from the old Batman series,
where Commissioner Gordon would pick up the extension in his office and it
would ring the phone back at Wayne's mansion.  Is there a way to duplicate
this functionality with Asterisk?

I just need asterisk to auto-dial an
extension when I go off-hook on another one.  For instance, I have two SIP
phones, Brian and Susan.  When Susan goes off-hook, it should automatically
ring Brian, without any other activity taking place.  If Brian goes off-hook,
it acts like a normal extension.

Any ideas?

Undrhil