I used a loft cut to create an opening in a part.  I'd like to create a plug for the opening by using the original part prior to creating the opening and using the same loft definition to remove everything outside the loft boundaries.  Can't seem to find anyway to do this.  I'm probably missing something obvious... help!

Basically, instead of cutting the inside of the loft, I want the inside to stay and everything outside the loft to be removed.