You can place a wall in the "doorway" and set it to be visible until the dialogue is complete, then set it to invisible. I had that going for a while in mine until I got frustrated with encounters not displaying right in one of the rooms and changed it.
That's what I'm currently doing based on kikii's suggestion. I placed 2 large portcullises and only one shows up (so I can have one down like a closed door, and the other raised). Maybe I just have to mess with the Y position rather than trying to move it via 3D mode. I'll have to mess with it more when I get home from…
Hmm....tried that, and still not working right. When I go into 3D edit mode it won't let me target the door to raise it. Also, I'm planing on having 7 prisoners, 1 to a cell, any ideas on how to best set that up? I guess opening the door should free the prisoner rather than dialog? Who knew something so simple sounding…