Hi Dan,
You would only need to control this via Translation Rules, you would apply the rule via a Translation Profile, and in order to make sure it works you need to apply that profile to your Dial-Peers.
You can test this if you have the time by duplicating your dial-peers and using a different prefix for dialing out, this way if it works you can delete the duplicates and then get your main ones to run with the profile setup.
I hope this gives you the basic answer you were looking for, I am not aware of any other format that is easier or that can do it.
Cheers,
David.
Cheers,
David Trad.
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