headlight clip

I have a 2001 Honda Civic and was replacing a headlight bulb yesterday.

Ran into a problem of the retaining screw on the clip simply not being
there. I'm pretty sure it was never there, because when I removed the
rubber seal the clip just sprang right out. I never did see a screw on
the floor or hear one rattling around under the hood.

Of course, nobody carries the clip part of the headlight separately,
not even the Honda dealers around town that I've called up. Anybody
know what size and type screw to use?

I'm having a hell of a time finding a diagram of the headlight assembly
detailing each individual part....