Hi Lee,
It's a little complex. We have done this in a couple scenarios. You need to
create an MSI using regform for your extranet users. Then have your internal
users install the same form. Inside the form, you'll put some "hack" to tell
it where to "redirect" to if opened inside your intranet. The redirection
essentially opens the SharePoint form internally with the data. Another
option is to deploy a winform for your external users that submits an xml
with a PI which points to the internal SharePoint site. In either case, you
lose auto-upgrade. One final option is to have an externally facing website
that they use to get the template. Submit through a Web service that reposts
to your internal web site and fixes up the PI. The benefit here is that you
don't need to go Full Trust. Full Trust complicates things because of the
MSI or Digital Certificate which must be installed. We've done all of these.
Can't say one is better than the other. Depends on your scenario.
Hope this helps,
Patrick
http://www.autonomysystems.com/