After I thought about it some more, I think you should try this action from the manual
scirra.com/manual/132/common-actions
Set position to another object
Position the object at another object. It can also be positioned relative to an image point on the given object
If you make an instance so that when NPC on collision with door object, the NPC Set position to image point outside of collision box then you don't have to rewrite an event for every instance