There is a old german "tutorial":
If you know the structure of the map, you can easily copy maps into another
just by copy&pasting the .lnd files intothe other folder.
But you have to pay attention on the filename.
Edit: With that method you have to place the spawns and npc's again in on the new map. I don't know if the method of Professor Linebeck could be helpful with that. Didn't test it jet...