[bkreigsr]

The headlight bucket is welded as part of the fender assy.
Your bolt is probably holding a bracket for the wiper fluid or gas overfill tank. (you don't mention what year car)
Even removing the bolt will not leave you a hole as big as the one you're already looking at (drain hole[missing the tube]) Why drill another hole?
Keep in mind that that area is subject to wash from wet roads - that's why the drain tube was originally there.
Bill K