Triggering onFire for multiple players?

I'm trying to code it so that multiple players can be on the same computer using multiple controllers. The first player is still a Player (because for whatever reason the game doesn't like it when player 1 is an AIPlayer). I want to call onFire for a weapon I made, and calling $mvTriggerCount0++ will trigger it for player 1, but I want players 2 onward to be able to do that too. Is there a way to hook up $mvTriggerCount[1-3] to call onFire with the appropriate player's objects?

If not, how would I call onFire with the appropriate parameters?

- Feynt