Hey Michael. I think i know what you mean, you want it so that the door sits in the center of the wall rather than directly in front of one of the two tiles in the room.
What you will want to do is print your door, and rather than print an A wall to go with it print two IA walls, then clip them either side of the door. this will position the door in the center of the room for you. I have attached a quick pic of exactly which wall in the Heavy Walls set you want.