Container Preloader - Is it possible?

I currently have a movie in the form of an interface which has several empty movie clip containers each at some point have an external swf loaded into using code similar to the following:

btnProceed.onPress = function():Void {
if (_root.root.currMovie == undefined) {
_root.currMovie = “h2”;
} else if (_root.root.currMovie != “h2”) {
if (_root.root.activity._currentframe >= _root.root.activity.midframe) {
_root.root.currMovie = “h2”;;

The above code is loading a movie called h2.swf into a container called activity located on the main interface timeline.

I would like to be able to place a simple preloader on the container “activity” itself to check the filesize of the h2.swf or any other external swf’s loaded in to it and present the user with a progress bar until the movie has loaded and obviously play the loaded movie when successfully loaded.

This would be useful as the “activity” container will have about 50 individual swf’s loaded into it, so placing a preloader on every one seems a bit overkill and not very efficient.

Can this be done?
Can someone please provide me with an example or tell me how this can be done?