[SR-Users] How to use ruri-pattern with allow_trusted?

[voipspace voipspace]

Hi

Have used allow_trused to pass the allowed ip.
Now I want to check the request has a correct tech prefix.

With an entry in ruri-patten column in the trusted table for example 75622#.

So if calls are to olny be allowed when the "to" destination starts with
75622#. 

Regards