I had trouble with this too but then I figured how to: 1. Mark the territory 2. Place buildings you want in it (don't forget the townhall so players can capture it and place min. 1 house) 3. Create the hauliers (carter post) 4. After this click "objects" bottom left-hand cornor in the editor and search for the hauliers. Then click on it and mark what it should transport (you find this setup on the right side of the editor -> text: objectoptions.) Also you can change the affiliation at the objectoptions. So you can mark a land but place "enemy" buildings on it. Can be nice to make a szenario like a town and enemy units are burning it at start, so you need to "restart" building it up :D