You will need the Designer client installed on your PC. You will also need to ensure that the server is running the HTTP taks - ask your friendly Notes Admin.
Once you have that, you can create a database and, in it, a form that will record the request. If such a basic form works under Notes, you can put it in test on the server and be reasonably sure that it works in a browser. If that is not the case, you will have to review the functions you used and check whether they are compatible with browser useage (hint : LotusScript is not, but JavaScript is).
Once the request is recorded, you will need to devise an agent that will take the new requests and place them into the task queue of the Admin Process - not a simple task.
By the way, you do not go to the server to register a user, the Admin should use the Admin Client on his PC to do that.
Concerning the response mail, there is an issue : since you will have automated the process, the ID file will be placed in the Person document. That means that the user will only need to know the full server name, his own Notes name (canonical) and, of course, the password.
On the subject of the password, you'll need to find a randmization process for that too.
A nice project you have there. Lots of fun in perspective. Are you a Notes developer ? If not, you're going to need one.
Pascal.
I've got nothing to hide, and I'd very much like to keep that away from prying eyes.