Adjust length of SWF file in Elements 15

I have imported the Dog Paw Trail.swf file that Premiere Elements uses if you create an Instant Movie with the Doggie Days theme into a project of my own.  The problem is that I can't figure out how to make the Dog Paw Trail.swf play longer.  I have tried dragging the Trim From End to the right, but it won't change.  Is it possible to make the swf play longer?  If so, how?