Thanks homie!
Well, I already know this from the manual, but with this the door frame remains. Only the dynamic part disappear.
Let me explain what I would like to do: there is the defult scifi corridor elements and scifi doors shipped with FPSC.
I would like to cut a hole with the format of the scifi "pentagon" style door in the wall wehere the scifi corridor ends.
This was what I tried to do in Segment editor but I stuck
Edited:
Well. I found an alternate solution. Not the best, but works: I found a transparent texture here, and I replaced the doors frame texture with this transparent, then I used the method You wrote.