Searching for redeem code on already downloaded game

I have the original Spore loaded on my old computer but no longer have the case that has the redeeming code.  I've tried to check out the properties of the game to see if the code is there and am having trouble locating it.  I'd like to link it to my EA account but can't without the code.  My kids love the game and I'd like to wipe clean my old computer to get rid of it, but want to save the game.  Can you tell me how to find the redeeming code?