Aha, my speciality
how about DONT talk to him first, let him notice YOU. make a bit of eye contact to show interest. and when he talks to you, which he will, dont give away too much about yourself, let him take the lead. dont act too forward, afterall its only human nature to crave something you think you cant have. talk to other guys!! dont wonder around looking hopeless, act busy. And if you have noone to talk to, walk around and act as if you're doing something. also smile at the room, be happy, a guy is always attracted to that.
hope this helps!!