Possibly two ways of doing this...
Change the SIP ID of the destination extension to the full (external) number, but, that can cause unintended issues and really isn't practical if there are more than a few that you want this to work with.
Create a SIP Loop trunk, but, every call will use two licences, one out and one in, per call.
Stepan (SY) posted this back in 2011 with regards to DIDs, but it can be used with any call types/digits defined in the outbound rules...
Technically, the trick can be implemented using loopback SIP trunk.
1. create SIP trunk with 127.0.0.1:5060
2. create outbound rule(s) for this trunk. They should intecept all DID numbers
3. attach existing inbound DIDs rules to this trunk