Unfortunately, there is no documented API for working with
Captivate files, especially for those looking to embed Captivate
files directly into a custom wrapper.
There are known internal variables you can access, but those
are primarily limited to navigation and such. A good list can be
found here:
Link
to List of Published and Unpublished Variables
For a peek into the internal scoring routines, you might want
to take a look at the Actionscript files Captivate uses, which can
be found in:
C:\Program Files\Adobe\Adobe Captivate
3\ActionScript\AdobeCaptivate
Beyond that, you're already much farther ahead than most.
Best of luck,
John