Possible to adjust Built-in Variable

I am wondering if there is a way to adjust the built-in variables. My company uses our own cloud-based system for students to take modules. Our system uses JavaScript to track all the student has done and where to start the module from when they left.

The reason for asking that we would like to use the Storyline player instead of our custom player that we created. I would like the menu to know that if the student got up to page 17 of a 25-page module, that when the student comes back that P 1-17 of the menu is accessible.

Is there way to do this?