I have 3 gateways:
Telecom Italia on an analogue adapter

MessageNet (sip provider)
Skype

How can I select gateway by a prefix THAT THEN GETS DROPPED before Dialing..

Example I would like to have

All calls beginning with 9 Sent to MessageNet , DROPPING THE “9”

All calls beginning with 7 sent to Skype, dropping the “7”

Otherwise use telecom