Non-ideal, but you could use mod_db to store the ${uuid} (value) against the ${sip_call_id} (key), then do a lookup over RPC to find the UUID you need. You'd need to set it within dialplan on every call that you're interested in, which you could do at the start of the dialplan.
I'm not sure if there's a way to query it built-in, though making a patch to add that ability should be easy since the uuid-call_id mapping is already stored within the sofia db. Using that would be much better.
If that DB is ODBC then that gives you another option, querying the sip_dialogs table yourself.