Somehow I was able to combine Grafton's Projection Flashlight shader with this one. Right now it's only the flashlight + 1 room light, but I'll add more lights later on. I'll post the code later tonight (I'm at work).

I say "somehow" because I know pretty much NOTHING about how shaders work, but with some "advanced" cut-and-pasting I was able to figure it out. Thanks to the OP for this!