Problem with targeting a function

I’m trying to call a function (comeon()) that is in a loaded movieclip (haitch), loaded into level3.

I thought _level3.haitch.comeon(); would do it but it doesn’t seem to work, and I’ve even tried built in functions (play()) to see if I can target the loaded movieclip with no success.

Any ideas?

Code for the holder swf:

var haitch:MovieClip = this.createEmptyMovieClip("haitch", 3);
haitch._x = 484;
haitch.loadMovie("hbox.swf");
_level3.play();

The swf loads in fine, but I can’t target it.