Share 'Comic Coloring in Corel PhotoPaint X4 ?'

Heya everyone, I have Corel PhotoPaint X4 and wonder if anyone uses the same program for coloring their comic book art? I'm looking for the best or most efficient way to to color in layers. One layer for the Black inked line work, then a layer of colors underneath and coloring special effects on top of the inks. I just can't seem to figure out how to make the open areas on the Black to be transp…