Hi Ted and Luce,
It can be done - I've done this in the past - give me a little time to dig out the procedure and I'll post back.
The insertion of an ending is easy

it can be done by editing the control track. Monitor the sequencer playback and make a note of the bar number where you wish to insert the Ending. Then select Program Menus > Sequencer > Record & Edit > Step Record > CTL. Cursor forward to the start of the Bar number noted earlier and then press Intro/Ending 1 or 2. That should do it

The insertion of an Intro is a bit more complicated......
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Willum