I had a brainwave! If your doing this at a table (lets say a restaraunt for your friends or something similar, but not the cafeteria) you could do a simple backpalm to vanish the card, but when you go to reproduce it, exaggerate the waving of the hand and lap the card. Then when you are supposed to "pluck" the card out of the air, act confused when it doesn't appear and check your hand as if you were looking for the card, while doing that, use the misdirection and use your free hand to put that card in a safe place (or palm it and put it back on the deck).