Hi there ne033x,
Ive had a quick look at flights available and unfortunately there doesnt seem to be much for Copenhagen to Dublin. However its not all bad news because flights with easyjet are pretty cheap but youll have to fly from Copenhagen to london stanstead andthen stanstead to dublin. I use
www.skyscanner.net , a great resource for finding who flies where and prices.
Alternatively, why not think about flying to stanstead and making your way to holyhead in north wales then jumping on the boat to dublin? Hitchhiking is an option, thatll be free, and there are a fairamount of trucks that head to holyhead for the crossing to Ireland. Its a bit of a drive but youll see a lot of England and wales in the process.