How can I pass a variable to a profile field in Moodle using Storyline?

Hi all,

So I followed the steps in this article: https://www.articulate.com/support/storyline/how-to-send-the-value-of-a-variable-to-an-lms?_ga=1.247718599.1989366233.1469498808

It seems to work great except it is not actually writing it on Moodle. I needed to ask the learners for an alternative email before they start their lesson. From the article above, I was able to ask and it shows up on the result slide, but that's how far it goes. What I need it to do next is pass it to a custom field I created in the learner profile field in Moodle. I can't touch the PHP...more like, I have no access to it (vendor), so I need something to pass the variable without needing to edit Moodle. The custom field is there, the variable is captured, but just not getting written to in the field.

Can you guys refer me to an article that I can follow or a solution perhaps you've done to do this?

Thanks