Automation of User invites in Customer Portal

Hi,

I want to know if it exists a way to automate the user invite in the Customer Portal via a custom Form, via api call or other via without user interaction.

I would like, for example, create "Students" in my database using a Form and add them automaticaly in my Customer Portal.

As I can Allow Self-Registration in the Customer Portal and set the default profile (in this case one that filter the info related to the Students), I thought I could create to every Student an account to my Portal just when I Add a record in the database, but I cant find a way by myself.

Hope there's a way to do this or an approach.

Best regards,
Dani