Hi Dennis,
Hope you are well !!
My first thought as well, just copy ARRL DXCC, add/subtract from that. I believe the entity can be determined from the callsign only because CQWW does it from an ADIF file without any other identifier other than callsign. I will look to see if they have prefix specifics. My only concern on doing it this way was having almost duplicate DXCC lists with CQ's being the hardest to maintain.
My second thought was to create a DXCC-CQ list but only populate it with those six entities that make it different, but, don't know how LOGic would read that list first and if no matches then go to DXCC. That list would be small and very easy to maintain, but, more work to incorporate.
From a contesting perspective it is only a multiplier issue, maybe simple is the best approach.
Thanks for looking !!
Brad, N8GLS