Routing Calls

I have two PBX Systems A&B installed. I have a SIP trunk between them so extensions are able dial each other from both sides. A is connected to an international SIP Trunk “1”. All Extensions registered to A are able to dial international calls through “1”. I need extensions registered to B to be able to dial international calls through System A. So the call will be routed from B to A, then from A to trunk “1”. I tried this by creating an inbound route that matches anything and sends to a custom extension. But it did not work. Any ideas? Ana Many Many Thanksssss