Neil -
Sure, you should be able to get that setup. I would suggest that you
first get acquainted with using our service and how we do list
management:
http://www.mailchimp.com/features/build-manage-email-list/
Once you've done that, spend some time with the API documentation:
http://www.mailchimp.com/api/1.2/
listSubscribe, listBatchSubscribe, campaignCreate, and campaignSendNow
are all methods you'll end up using. The methods will make a lot more
sense if you've used our service via the web interface first.
jesse