Remember - my wife needs to be able to use this and she will refuse if it requires more effort than Quicken (or any other Win32 app).

If I can launch the webserver and IE and point it to the right page, all in one click ... perfect! If I can't, then I need to find something that will.

I'd suggest installing the webserver as a system service, but there is no reason you couldn't check to see if an instance was running, daemonize the server if it wasn't and launch MSIE all from a launcher perl script. This is Perl, after all :)

I think the advantages of being able to do real CGI would outweigh the pain of getting this working -- and then of course cross-platform is a freebie, so it ports nicely.

really if you want a nice user interface though, with drag and drop, dialogs, and all the fancy GUI things that Microsoft and other non browser programs offer, the browser approach might not be the best way to go. Though you have domain knowledge in this area, it's a TON more straightforward to make a Tk application. And, regardless of what has been said about Tk, it can be made to look fairly clean -- especially if you make your own icons and adjust colors away from the default gray and stuff.

Don't forget to look at webmin -- you might be able co-opt a good deal of web server code (if it's not heavily Linux centric), it's BSD licensed!

To solve this I create an invisible frame that refreshes itself every second. Then I can simply send a small bit of javascript to this hidden frame that causes the main frame to reload itself. Already I'm getting in to portability issues having to use javascript.

Maybe I'm just a stickler for design concepts, but this sounds really like a bad unmaintainable way to go. Applications shouldn't have to do this. So yeah, try the server, or bite the bullet and look at Win32::GUI or Tk or even Wx.