Torx 20 screw in back of headlight - does anyone know where I can get a replacement?

Hello - today I replaced the HID bulb on my 05 Acura TL. For the most part, it went well except I dropped and cannot find the T20 screw that holds the cover on in the back of the headlight assembly. This is a very small crew that requires a torx 20 security bit to remove.

Does anyone know the part number for this screw or where I can get a replacement?

Thank you!