Newbie ? on Nero editing from hard drive

I have captured 3 scenes from a dvd onto the hard drive and have it in the Nero vision express 3 saved. I now want to use only parts of the scenes and am having trouble with this. Is there a way to just watch the scene and record the parts I want to keep (like on a vcr- pressing pause/ rec as needed)? I have an external dvd-r I can use to play the dvd to the program if needed.
The help part of the program is a little confusing.

anyone?