Show a Storyline in a Storyline with controls

I've done some searching, but haven't been able to find a solution.  I'm building a course that will be LMS hosted and my customer would like it to link to a published Storyline course that is web based.  I've tried using both a "jump to" link and a web object.  Both work to get the file opened, but my issue is with figuring out how to move on once the linked SL file completes.  That course doesn't have an exit button.  If you close the window, you close the whole course.

I'd like to be able to have a short narration to introduce the linked course, after which the user presses a button to have the other course play/load/whatever.  When that course is over, they use the next button in the "parent" course to move to the next slide. 

Since this isn't media, none of the start/pause/stop options for media work.

I'm almost certain I've seen this done in tutorials, but I'm apparently not using the right words to search.

Thanks for your help!