for a good guide of spotting at CPH. Unfortunantly, it's in Danish, so I've translated the text to English for you:
Spot 1: "Flyvergrillen"
"Flyvergrillen lies side by side with runway 04L/22R and taxiway Alpha. If the 04 runways that are in use, this is the place to be for some great closeups.
It's also the only spotting place at CPH where you can buy food and drinks.
Spot 2: "Englandsvej"
Englandsvej is a public and rather large road, which runs under runway 04L/22R in a tunnel. It's relatively close to the heavies' rotating point (unlike Flyvergrillen), so if you want some action shots, this is the place to be (that is, if rwy 22R is in use).
Spot 3: "Tømmerupvej"
From Tømmerupvej, there's not a great view, however, if you explore the area around it, you'll finde some good points for taking pictures of the aircrafts on short-short finals ro runway 04L.
Spot 4: "Store Magleby"
Store Magleby lies very close to the treshold of rwy 04R, and you also have a great view of the maneuvring area as well as the apron (although you might need a pair of binoculars for that, it's 2 miles away!)
Spot 5: "Kystvejen"
Kystvejen runs along the northern borfder of the airport, and along its way it passes SAS's hangars, the treshold of rwy 22L and DHL's cargo apron. Usually, Thai parks their 747 outside SAS's hangars on its layover (a couple of hours during the day). On the plus side: There's a small supermarket (like a Trader Joe's in the US AFAIK) and a McDonalds (well, plus or minus depends on who you are
) only a short walking distance away.
Now, you mentioned that you're only in transt for a few hours, so I'd recommend either spot 1 or spot 5, as they're both within a short walking distance from the airport. Also, you'll be able to get some food