Make sure you inlude it first (hope I'm not insulting your intelligence), then call MagicLoad("myMWDBworld",firstobject,firstmatrix). The firstobject and firstmatrix variables can be a little tricky. The MagicLoad function loads all the matrices and objects you put into the mwdb file the standard DarkBASIC way, so you need to specify where to start placing objects and matrices into memory. There could be some bugs in the include code since it was written in DBClassic, just go in there and make sure all the commands are DBPro commands.
Juvenile Industries
Current Project: KillZone(FPS)
Soon to come:An rts, and a snowball fight game