You would have to build a camera for the light. Just to make sure it's working 100%, switch to your top view and create a new camera. Now hold down shift and pick whip the camera to the light you want to look through. On the camera open up the position parameters and 0 out everything and the camera should be in the exact position and orientation of the light and if you move the light the camera will follow. Just turn off the camera when done and you can get back to your scene.
Johnny Cuevas, Editor
"I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work."
---THOMAS EDISON on inventing the light bulb.