Can I port my number from a prepaid account to postpaid account with AT&T?

I was needing to know if I can keep my current Net10 prepaid number when I activate a 2-year contract with AT&T. I know when you transfer numbers they ask for an account number from your previous carrier as well as a social security # & a few other things. But prepaid phone accounts don't have an account number & don't require your social security number. So is there a way I can keep my Net10 prepaid number when I switch to AT&T postpaid? And if so, do you think they could do it when they activate my service at a Radio Shack, Walmart, Sams Club or even an AT&T store? Thanks for any & all answers!