I'm doing a bath remodel and want to move the main stack about 6-10". It can stay in the same wall, but I am cutting into that wall to put in an alcove (annexing a closet) and need more width where the stack sits to put in a W/D. The pipe is 50+yrs cast iron. Is it possible to essentially move (well, cut out and use ABS) just the piece of the pipe that is in the room (just below floor line to just above ceiling) and use 2 45 degree angles to tie back into where it is now in my crawlspace and attic? I'm trying not to have to move the whole thing esp in the crawl space where it ties into the sewer line (do I have that right?) and would rather not have to cut a new vent hole in my roof. I know zip about plumbing (could you tell??) and will hire it done, but just want to know if it's possible/recommended?

Thanks