Mark,
I was thinking you can copy just the range of measures you want. You could certainly do that within a song... say to copy measures 13 to 16 from one track to another. Then delete the original track.
Other than that, possibly you need to dictate the length of the song in a control track.
I would ask you to send a file but my KN7000 is not set up as I have visitors here for a few days, so I can't try it right now.
Best wishes,
Mike