Picture and Fax Viewer Hack?

If anyone can figure this one out, you RULE!

I want to modify Windows Picture and Fax Viewer slightly, or rather change the behavior of double clicking a JPG file.

I want to cause a slideshow to automatically start when double clicking a jpg image, just like when you click "View as Slide Show" on the left side menu thingy, instead of just "previewing" it in Picture & Fax viewer, or find someway to go completely full screen with the image instead of the lame white background w/ little icon tray at the bottom of the picture.

I don't want another program to install...as there must be a way to do this.

I searched the registry to try to find what command envokes a slideshow when you click "View as Slide Show". I found something like @shell32.dll,-31876 or something similar. I tried changing the program that opens a jpg image to that same command and several similar things, but it won't take it. Any ideas?

And, yes, I COULD just click "View as Slide Show", but I'd rather just double click the image file :)