DnR, I do this the opposite way. Whenever I install a system with PRI, the CO trunk group points to a CRT using Caller ID to route, with E and + pointing to a second CRT routing based on DID.
That way I can intercept any calls from the harassing caller and dead-end them regardless of which number they call and after checking my CID list, I then route based on DID normally.
Just a thought.
