loading movies without replacing?

I want to load additional info (movieclip or swf) into an existing movieclip holder without replacing the current movieclip. The new layer has to zoom and pan in the same way as the existing movie. I can load movies into movieclip holders, but as far as I know they will always replace the existing ones. I use the script beneath:

mc2 = new MovieClipLoader();
mc2.loadClip("kaartarchi.swf", content_clip.inner_clip.ImageHolder.Content);
mc2.onLoadStart = function() {
loader.start_(content_clip.inner_clip.ImageHolder. Content);
};

Is there another way to do this? I use Flash 8.