What can i say to get her number?

This title sounds horrible its not like bad. I don't want to just "pull", there is a girl I have liked for abour 3 years, we used to be really good friends but for the last year I haven't really spoken to her and thus lost her number. I want to tell her how I feel but I'm too shy and I dont think she feels the same way. But I will be seeing her for possibly the last time ever in a few days at a party and I want to get her number and start texting her again and see if we get to know each other better something would blossom. what can I say? what should I say? I even want to be friends with her again, closer friends anyway but we just lost contact really what do I say?