Yes.
The loadMovieNum action should be on the first frame of the main movie's preloader, along with a stop action. Once the movie is fully loaded, with it's own preloader within, or monitored from a preloader mc or an onEnterFrame function on that same first frame, the playhead is move on the next frame where the main movie is then preloaded.
This would assume there would be a stop action on the first frame of the loaded movie, so that it doesn't start to play until told to do so.