I think this is not possible, because the tracks are in an .arc and in the .arc is the model in .bmd. So you have to find out how to convert the course_model.brres from the mkw track into course_model.bmd. But when you would be able to do this then you need also other files in these formats: .btk, .bol, .bti and other. And this don't exist in an mkw .szs. And as I know nobody know for what the files are, because for porting from MKDD to MKW you only need the .bmd.