I already own chaser since it came out in the first place on cd and is there anyway i can add my cd-key here and get the game digital gog version?

No, if you want it here, you must buy it again.

OK. Thx for the info

I think you have to buy it again as the old version is changed and the new version of chaser are having new features and specification are added in these game, so don't go with old set buy the new one to play these game.