Custom Emitter shape

Hey there,

I am pretty familiar with Trapcode Particular at the point but cannot figure this one out for the life of me. Perhaps it's not possible, but it seems like it should be, so maybe you guys can help. Basically the effect I need to create is steam/smoke coming off of a vampires face after he get's splashed with holy water. I have already created tweaked the parameter to make the look of steam, but I want the particles to only emit from the vampires face as his face moves around. I don't want to merely track a null object to his face and make the use a sphere for an emitter shape because it won't look quite right. I have created a clean luma matte of his face as it moves and would like to use that luma matte as the custom emitter layer. When I do however, I see no particles at all. The turned 3d on on the luma matte layer and boosted up the particles per second and still nothing. I just want the paricles to emit from the opaque area's of the luma matte I created. Is this possible. PLEASE HELP! Thanks a ton in advance for any advice!

Brandon