If you could use medium format and shoot without the window glass, I would do that first. If the glass is unavoidable, place the camera as close as you can to the window, and minimize the light coming inside the room to reach the part of the window glass near your lens. (Carefully cover with a dark cloth or cardboard box without blocking any part of your camera's sight)(posted 8114 days ago)Did you try polarizer? Orange or yellow filter?
Unfortunatelly, I don't think you can do a lot in darkroom about this particular problem.