Filter effect transparent mc

Yo.
I’m using this tutorial, http://www.kirupa.com/developer/flash8/filter_effects2.htm. The effect I’m after is highlighting parts of a photo, so the mc that I’m trying to make glow is a trace over the shape I need from the photo. The problem I’m having is getting the traced shape transparent so i can see the photo underneath. Every method I try removes the glow aswell. Any advice? Cheers in advance.