Just wondering where the LE code is on Steam? Is it like a CD key and pops up in a window on the overlay or is it emailed to you?

http://www.gamesas.com/redeemcode/

Make sure you login using your crysis 2 game's ID and password and not any other account, if you have more than one to begin with.

Still doesn't work for a lot of people anyway. I'd say don't waste your time and just play the game.