Superimposing an external sfw(old film grain) onto another swf

hi there,
i’ve been doing cartoonanimation in flash for two years now, but i heve never been an actionscript hero. recently i read the tutorial on “old film grain” and i was wondering how i could get this nice effect superimposed on my existing swf’s, so they look like i found them in an old shoebox on the attic!
thanx a million
stinky mess