Wow, what in the world happened there?
You may be able to do an online search for salvaged parts that match you body color. I am guessing that you will need both the upper part that is missing, and the lower part that is still there (as it looks broken to the left of where that high mount light should be). The light itself may be yet another separate part. It may actually be better to at least visit a body shop and see what they can find for you.
In any event, good luck and let us know what you find.