I'm not an expert on AI installs yet but it seems like the problem is that an HTML document is not an application and cannot be "launched" per-se.
What you need is an application that tells the OS to launch the HTML with the currently associated application (IE, Netscape, Opera, etc...)
I've written a utility that can do exactly that...
http://www.3feetunder.com/krick/gorun/
You would probably want to run it using method 4 in the overview using a gorun.ini file.