Calling Party Xfer and Retain Control

Hi folks,

I’ve got an issue with transfer, specifically here is what I want to do:

Internal extension dials a number which is external to the Asterisk ( say, a 4 digit Over a SIP trunk).
This Call is connected and live
The original internal extension then issues a conference call to an out side PSTN destination and all three legs are connected.

I can certainly establish the first two calls, but bringing in that third one seems to be a challenge. I’m using visual dialplan, and the dial element and xfer element do not seem to see any call control past themselves. In other words you can’t script for subsequent call treatment once you’ve dialed or transferred. That means I have no way of bringing in the third call leg…

Any thoughts out there?