Sven, I've taken this route many times, it's easy....
From Belgium; Antwerp (B) , Eindhoven (NL), Venlo (NL), Essen (D), Hamburg (D), Kolding (DK), Odense (DK), Copenhagen (DK)
You have to pay for 2 bridges, the one in Odense and the one in Copenhagen...
Then your in Sweden and head North
Jelle