how to set-up a decal to a polysrf to get a solid-effect?

[mackl]

Hi-

i would like to map an polysrf , so i get an effect like a solid with a lot of wholes.
I`m going crazy with this.

[URL=http://img9.imageshack.us/i/planarandsolidlike.jpg/][IMG]http://img9.imageshack.us/img9/6838/pl



Now- i get only an effect like a two-sided srf



please help

Thx


Mackl