Thank you! I will try that out.
Just for anyone else's future reference, I realized you can "log in" as another user using GetSessionForProfile(). So if the other user is offline, you will be able to modify their data (for example, to increment an attribute for number of matches they have).
I believe this way, you can also do what JasonL said and TurnShieldOn() for the other user, stopping them from being able to match anymore.
Correct me if I'm wrong.