1.You can add multiple lights in an array to simulate the roof-light.
2.You can use poseray ( http://mysite.verizon.net/sfg0000/ ), import OBJ files.Then convert your light to "array" and use povray renderer (povray.org) to render.
3. Import OBJ in Kerkythea (www.kerkythea.net), replace lights/materials as needed, render.
Hope this helps (at least a little bit
)