Thanks.
I think Mary is right - once you have an example AICC course url/package this will become a lot clearer to you.
When I say publicly accessible - I mean via a website url (like moodle.org) that anyone in the world can access) - instead of an internal website that is only accessible by someone on the organisational network - many corporate/government moodle sites aren't publicly accessible and you have to be on the internal network or VPN to view the moodle site. The external third party AICC server will send an http request directly to the url of your moodle site to request information, instead of doing all the work through the users browser like a normal SCORM package does.
Moodle requires outgoing http access for RSS feeds to work - so if you have used the rss feed block on your site, and it populates/updates the content when cron runs then your web server will already be set to allow outgoing http access - other tools like plagiarism plugins in moodle also require the web server to allow outgoing http connections so they can post data to external systems etc.
the AICC HACP zip packages contain a single config file that provides the information required for Moodle to connect to the external system - the content still sits on the external site.
I don't know what knowledge the external party has on AICC HACP - I'd probably ask them if they have a csv file with a list of the courses and the aicc hacp url - if they only have the zips you'd need to add them that way or extract the files in the zip, open the config file and look at the url that is included in the config file.
think of AICC == SCORM - you can have a single course with multiple SCORM activities(and other activities like a feedback activity for your users to let you know how useful they found the courses, or a certificate activity to give them certificates for completing the packages), or you can use the single activity course format and have a single course for each AICC package. I'd guess the external courses are categorised in some way - you may be able to reproduce that category structure somehow by grouping the AICC packages into courses - In the MELL example I gave earlier I grouped the packages by product type and had an MS Word course with all the MS Word packages, a networking course with all the networking related content etc etc.