I've found just the opposite to be true with undergrad, but I can see how professional/graduate would be different (in which case, I need to figure out how to get my in-state next year). When I was at MSU, they wanted me to be in-state for reasons OTHER than higher education for one year and then I could be in-state in the school's eyes. That meant taking a year off of school and was not an option, but I finally got them on some obscure technicality and they gave me retro-active in-state (after 1.5 years). The best way would be either to ask the school or just make no mention of out of state from the beginning, but once you ask the school, they probably look pretty closely at your app. Good luck, I know that it saves a ton of money, but I don't see why they would be so anxious to give students in-state when they're making so much money off of them.
Jd