Hey question for all you experts!

I am flipping a property A to C (short sale). How should I structure the paperwork so the C buyer can still qualify for the homebuyer tax credit?

Originally it was AB to BC double close short sale, so I am currently stepping out and allowing a contract from C buyer to A seller, and getting paid an assignment.

QUESTION: the C buyer went under contract with me (B) seller just in time to qualify for going under contract for the homebuyer credit. If I draw up a new A to C contract, it would be AFTER the contract time period for qualifying for the homebuyer credit. Therefore, it seems that I need to keep the existing B to C contract, and actually assign it, so that contract falls into being executed within the original timeframe required for the homebuyer credit.

Any thoughts?
#1 can the guy still qualify for the $8k tax credit if the contract is assigned
#2 is there a way to make a new a to c contract (without backdating it) in this situation that would still get the buyer the tax credit?

thanks,