The full DCI rules are here:
http://www.wizards.com/default.asp?x=dci/doccenter/homeUnder section 604: "Star Wars Miniatures models released by Wizards of the Coast LLC are legal for tournament play.
Players must have the official corresponding stat cards for all registered miniatures."
Maybe you can contact someone else who is going and borrow a card for the mini you need to use. Some players bring extra stuff when they travel and might be able to help you out - or get there early and maybe someone can call a friend to bring the card. Otherwise, you might have to take an alternate squad with all the pieces. I feel bad for you though. In the future, you might be able to match the card on Hothie's Orphaned Card List under the Trading Forum -
http://www.bloomilk.com/Forums/default.aspx?g=posts&t=5940, but that doesn't help you this weekend.