Need help setting up an extension to forward all its inbound calls after two or three rings to a secondary extension. The main extension receives calls from outside and inside the building, so when anyone hits that extension and it's not answered in two or three rings it will forward to the secondary extension.

Down and dirty, Set call forward no answer
#6031 XXXX 12 Redial

The 12 is the number of seconds you want it to ring before it forwards.

This is making a few assumptions about your configuration.