Find this grand

Playing teams, you are in first chair, all white, and you pick up these cards:

Kx AQxx AKQ9876 --

Your partner's hand is this:

AQJT Kxx T5432 7

Grand is a laydown, but how are you going to get there?

At our table, Tammy opened 2C, and I responded with an artificial and forcing 2D. Lefty preempted 4C, and Tam bid 4D. I asked for keycards, she showed 3, and I bid 6, knowing we were off one keycard. We don't have any agreements on how to show a void when you also have 3+ keys, but even if she could show an unspecified void, I'd never believe it's clubs. McKenzie had some system suggestions for getting there, but I do think it's a devil of a hand, especially with the interference.

At the other table, the opponents found the grand, but only because our teammates attempted to sacrifice 7C over 6D. Shucks.

So -- how would you and your partner find this grand, with or without the 4C overcall on responder's left?