Not likely. They'll probably just pull the companion off the flight. Several years ago, this probably would have worked. I've heard from multiple WN folks that they are cracking down on CP "abuse." So I probably wouldn't try it now.

In the past during IRROPS I've split off from my companion before and everything has worked out just fine. But I tell the GA and Ops agents about it right when I first ask about rebooking.

OP: I'd just book AAA-DEN for you and the companion, then pay for him to go DEN-CCC. It'll still save you some money and more importantly a lot of potential hassle.