How to initialize text variables from an external text file?

Hi Heroes,

I'm creating a learning activity/game in Storyline.  Its purpose will be to supplement live instruction delivered in an instructor-led format.  The SL game is to be delivered to the instructors during train-the-trainer.  

Here's the problem for which I am seeking a solution:  We would like for each trainer to be able to customize certain text variables in the game.  And, to have their customizations be persistent each time they launch the game.

Our thought is to define text variables for the slides where we will need this flexibility.  Then, initialize each text variable from an external text file each time the game launches.  (Each trainer can modify the text file to suit their respective learning objectives.)

Any advice on how this might be accomplished?  I know it'll likely involve javascript, but it would be a great help if I can get guidance from any of ya'll who may have tried something like this before, and specifically get guidance on the code needed for referencing the text file and then setting the variables from content in the text file.  

I hope that makes sense?