[cyberactive]

I realy want to do it simple.

The register.tpl does not register a customer in the database.
The admin generates an account for the customer after approval.

So you can say, its just a form, which will be sent to the admin of the shop.

When I look at it now, it IS just a form. Nothing more, nothing less.
The admin has to enter the customers data by hand anyway.

Looked at your MM add-on. Looks promising to me. I will dicsuss this with the site-owner.