I am playing around with wallpaper settings for XP workstations. We have
Active Desktop turned off, so we cannot use Group Policy to display a
windows wallpaper.

I looked under the Windows XP tab in a User Policy and tried to use Windows
Desktop Preferences. The issue I have here is that there are only two
options: center and tile. I need the stretch option available as well,
since we have different monitors of various resolutions and we are trying
to lock down a default wallpaper companywide that would fill the whole screen.