Creating User Accounts from secure external site.

Hello, I want to start off by saying “Thank You” to all of the contributors to this forum. You all have saved me so much time and taught me so much. Thank you!

My question is “How can I create WordPress user accounts from a secure external website?”

I have a pre-existing payment processing system that will provide a secure page once the payment has been approved. I would like to create a form on that page in which the user will fill out his or her account info which then gets passed onto WordPress for access to protected content.

Any help is appreciated!

Thank you!