XF 2.1 Best/easiest way to automatically register users using another db?


Does anyone know, or have any suggestions, on how to automatically register users using another database?

I presume it will take a custom solution, but my main question is: What development path do you think is the easiest approach to accomplish this?

Thank you.


My Situation:
  • My users currently create an account though my website's login page
  • Their information is stored in a MySQL database (called "main website's database")
  • I have a separate instance of Xenforo running on a separate server
  • I would like the users to be automatically registered with xenforo using the info provided in "main website's database", ideally updating their info each time they visit the forum.
I'm sure it's been done before, so is anyone familiar with a simple (or semi-simple) solution?

Thank you.