Membership Feature Request: Can I create a registration form for existing users as well as for new users?

I want to create a form that allows me to "Register Existing Users as well as "Register New User." For existing users, I am guessing the form would store contact information in a database and existing users can search for their profile, pull it up, and register on the current month's event with their information, but also have new users who attend our event be able to register on a "Register New User" button. Is this possible?

Unfortunately, we do not currently have membership features available on forms.

I have attached a feature request ticket to this thread and forwarded it to our developers for consideration.

We do not have any ETA for when it will be implemented, but we will let you know if we have any updates.

That is indeed a possible solution provided by @grade4pagasa. The http://demo.interlogy.com/pm3/ 

Do let us know if that software fits your requirement.
Regards.