Headlight Retainer Clip

Does anybody know where I can get just one headlight retainer clip for my 2000 GMC Jimmy. I have had it for 3 weeks and one of the headlights wasn't fastened very good...so my boyfriend tried to fix it and one of the clips ended up falling into my engine and we can't find it. I would rather not go to a dealer because I'm sure they would charge me an arm and a leg! Thanks!