Russell:

Perhaps what you're thinking of is the "Song Form Maker". (From the "Tools" section of the main menu, click the down arrow and select "Song Form".

Not sure what you mean by "Line 14" and "Line 17" but this tool can be used to "jump around" the song. Say the first part of your song is bar 1 to bar 56. Set that to be the "A Section". Then the part you want to skip is bar 57 to bar 64. Set that to be the "B Section". Then the remainder of the song is bar 65 to bar 80. Set that to be the "C Section".

Now create your song "Form" at the bottom of the Song Form Maker window, to be "AC". BIAB will play bars 1-56, skip 57 to 64, then play 65 to 80.

Not very elegant but may be usable.
Good luck!
LLOYD S