New on gog, trying to bring some games from steam to here. Game in question is the witcher 2 enhanced edition, gog sells it, but does not recognize my cd key. What to do?

A CD key would be to install the game from a CD/DVD, not a code to redeem a game.

Might try Reclaim your game... assuming it's supported. but glancing at the games list on the page, i don't see it there.

You should be able to get a free backup copy by going to this link:
https://www.gog.com/witcher/backup

That looks like what he needs.

That worked! Strange, I had no trouble unlocking the witcher 1 with the default redeem cd key page.
It seems steam does not have a key for TW3... Hmmm... Last game of the saga I wanted to rendeem here on gog. Alas.

Give it sometime and Witcher 3 will probably become redeemable here. :)