If you are trying to do what I think you are, fear not, it's entirely legal and acknowledged by CO as a valid (if perhaps unintended) perk.

If you book your wife's trip using your miles, your status and benefits (except EUA) will be available to her, regardless of whether you are traveling on the itinerary. That includes EliteAccess on the boarding pass, your bag allowance, and your elite status noted.

To answer your question, you could split the passengers on to different PNRs, then cancel the reservation of the passenger who does not wish to travel.