NSM in PCOMP

Hi,
i'm trying to put some NSM (non-structural mass) in my model. I'm using the Nastran interface of Hypermesh. I already set the value in the PCOMP property shell.
What I have to do now? If i simply mesh my surface, NSM is not counted when I checky the total mass using the available utility. Why?

Thanx, cheers

Simone