heh - I spend a lot of time answering that same question as it comes up a lot. :-)

Firstly - for a package to be a SCORM it must have an imsmanifest.xml file - this file contains all the info about the SCORM (including the initial launch page) - a link to an html file will not work. you can only link to an imsmanifest.xml file or a zip file containing the imsmanifest.xml file.

But - you can't easily host unzipped SCORM packages on an external site - SCORM uses JavaScript for communication and often contains flash content that tries to communicate with the JS.

Both flash and JavaScript prevent cross-domain communication by default - you can get around this if you have full control of the users browser like in a corporate situtation where you control the users desktop and can make group policy settings to disable the users browser security settings but this can be hard to justify to your IT dept.

IF your Totara site and your external store of unzipped SCORM files are on the same url then it does work as they use the same url/domain and Flash/Javascript won't cause issues.

for example if your totara site was http://demo.totaralms.com/totara and your scorm files were stored in unzipped form in demo.totaralms.com/scormfiles then this works ok. (as long as you point Moodle at the imsmanifest.xml file

I have heard people claim that the use of subdomains works too but I don't know if that is cross-browser compatible - eg http://www.totaralms.com and http://scorm.totaralms.com

There is a type of communication called external AICC HACP which allows for cross-domain communication as it doesn't use Javascript - this involves setting up an AICC HACP content server which hosts all the packages and entering the url into Totara and afaik there's a bit of work involved in setting this up and packaging your content in this format.

There's a bit more info on this scattered in the moodle.org forums - if you search for "cross-domain SCORM" it should throw a few of them up.

hope that helps.