I'm not sure why you'd need multiple cd keys, considering one cd key can create multiple profiles...
For those people who have purchase multiple copies of the game during the Steam sale, it is possible to have multiple DayZ characters by switching the CD key in the registry. This is not the same as switching profiles in the game (as that only changes the appearance of the character, not the associated CD key). The CD key switch is fairly simple and just requires to replace whichever regedit the person wants to play as before launching the game. I guess the person above would like to have this automated.