[cisco-voip] Putting a H.323 voice port in a call pickup group?

[Robert Kulagowski]

Centralized CM, remote sites.  MGCP has proven too problematic / 
unreliable, so I'm trying to migrate to H.323 only.

We have overhead ringers connected to FXS ports on 2821/2851 routers; 
dial the DN, and the device starts to ring.  What we do is call forward 
the main number to the DN of the ringer, so that if the receptionist is 
away, anyone can pickup with the Group Pickup button when they hear the 
overhead ringer.

All of this works if we use MGCP for the analog ports.

Is there any way to do this with H.323?