Get drunk and then slur how much you love her, that should do the trick, you won't have to avoid her because as soon as she sees you you won't see her for dust.
OR/
Try to just talk to her about something normal, like if you see her getting some food, join the queue and ask her what 's nice, that sort of thing. Try to engineer a situation where you could talk to her with out it being weird and stalker like, don't be too obvious.
If you do get talking, try to be a bit mysterious, don't cross over into friend territory, and whatever you do don't tell her how much you like her, hint at it, but keep her on her toes, if you're too easy then she won't be interested, women love a challenge.
Also, if you have any female friends that you are close with and that you trust, they can be a goldmine of tips for how to approach this sort of thing.
Failing that, just find the nearest slapper and throw her a bone. As burnboy said, it's a great way to get over someone.
Stu.