It seems like the Hilton Copenhagen Airport hotel sells the Copenhagen Card. It's right outside the airport building (walkable); just follow the sign or ask someone. (When exiting "baggage claim", go straight ahead and slightly to the right, past the DSB/train ticket sales booth, and then exit the doors on the right at the end of the airport building. The Hilton is just outside.)
http://www.woco.dk/tourist/what_to_s...openhagen_card