Fog Help?

[PuppetSerpent]

Hey everbody, I'm new to modding Amnesia and I've hit a small snag on my first project. For the first part of the story, I want to have the player escape an enclosed room by jumping out a window. The issue I have is that I want it to be foggy outside, but when I turn the fog on in the Level Editor it spreads into the room. Is there a way I can limit where the fog spreads to? Thanks in advance!