Even if you could use them in the engine, to my knowledge, the only LEGAL way to avoid complications is to buy the same pack twice, one for you and one for the other person. Sharing files the way you mentioned will likely cause you problems down the road.
I am a very blunt person. I have NO filters in communication. I say exactly what I think and feel. If you think im being abrasive, its probably a personal problem because usually, Im not. Win 7 64, AMD T1100 Thuban cooled by Thermaltake, 16GB GSkill Ripjaws series 10-9-9-9, 4 HDD's Saphire 6950 Flashed with 6970 Bios and all powered with Corsair CX750M