Custom player button for multi-SCO course

I have a SCORM 2004 course that is published to HTML5. I need a player button that will perform the "Exit course" action but do it via JavaScript.  I need to do this via JavaScript as I need to execute a certain JavaScript line just before this "Exit course" action.

Here's the full story:

We created a multiple-SCO course where each SCO is a specific language of the course.

• Language menu
• English course
• Spanish course
• French course

The "Language" SCO is not built in Storyline. It's just a language menu to navigate the user to the correct language course selected.

The other SCO's are in Storyline. In these I need a Player button that will navigate the user back to the Language SCO.  This button must do two things:

1. Execute a SCORM 2004 SetValue command
   SCORM2004_CallSetValue("adl.nav.request", "{target=menu_item}choice");
2. Exit course

I'm open to other ideas for accomplishing this. Thanks in advance!