Dave,
I think you may be working too hard at this. Because of security issues,
there isn't an easy way to transparently launch an .exe via the browser.
Your users will be exposed to the security message regardless. Also, as far
as I know (which isn't really that far since I've never played with HTA)
calling an HTA will only work from within IE. What if they're using a
browser other than IE?
I'd suggest that you have a page in your site for each application that
states the reason it's needed explains that if the user clicks the link,
they'll see a message and to choose "Open" or "Run" or whatever is
appropriate to launch the installer.
Using this method will alleviate the confusion and you won't have to waste a
lot of time learning HTA scripting.
