Integrate mailchimp signup int the backend add new user form?

I am looking to integrate an add to list drop-down box or checklist in the new user creation via the joomla back-end ( imageshack.us/photo/my-images/339/captureupc.png/ )
I wish to create a new user every time manually instead of the user creating their own account, and while doing this automatically add them to a mailchimp list. It would be easier to be able to add them straight from this back-end page, but if it cannot be done, is there a way i can get the registration page to show up only for a logged in administrator (no other user) and have a working mailchimp integration from the front end?


joomlamailer version: 1.7.2
Joomla! version: 1.5.23
PHP version: 5.2.11
MySQL version: 5.0.91