It would probably be easier to just make a unique object for warping in this situation. Just call it warp2 or whatever.
I'd make DestRoom, xx, yy, variables in the create event. Set them to whatever.
Collision with Player:
player.room = DestRoom
player.x = xx
player.y = yy
Then when you place them in the game set the creation code to where you want the player to go in each case. Anything else frankly seems like over-complicating it, unless I'm grossly misunderstanding the problem.