The problem with doing the copy you're trying to do is locating the desktop folder from a BAT file. You could use vbscript or javascript but there's just no guarantee that the user will have them installed or enabled. The only bulletproof solution is an EXE. I'll see if I can whip something up for you (I'll post a link here when it's done).

The proxy utility should work on all platforms from Windows 95 right up to Windows XP without any problems. It uses only the most basic Windows API functionality so there are no machine specific issues.

"Thing" projectors work smashingly well on both platforms. From one SWF you can generate two applications, one for the MAC and one for the PC. We've been working with a few customers who have already deployed projects built with this technology. That's helped us get some of the core player issues worked out