if they are in the same flash player you can target using actionscript, eg from a movie loaded into a movie clip in another movie you can target the main timeline (of the movie that did the loading) using
you'll have to add frame labels to the frames within your movie you want to be able to go to. you can't use scene names if the goto action has to target a different timeline.
in the embed tag.
(note the id in the embed tag is for Mozilla and it's variants, I don't have a copy of any of those browsers on this machine to test. but i think with that you can get the GotoFrame method by creating an object using document.getElementById on the embed tag, that is the "else" part of the function)