Hi Robert,
 
On the webex pages there is no way to do this via a API or from the common entry points we provide.  The APIs were designed so that if you wanted to, you could create your own registration webpage to gather end user registration.  Once your internal page recieves the enrollment information, you could send just the basic information (first/last name, email, and sessionKey) to webex  on the backend to register the end user for an meeting or event that has been scheduled.
 
Thank you
-Kingsley Lewis