You can (and SHOULD) install the MS-Windows port of the GNU Bash shell on the windows machine(s) -- believe me, you'll be glad you did, and not just because it gives you a way to make this script work the way you want.

The command line you showed should work fine as-is on any unix box -- I'm pretty sure that whatever "default" shell is invoked by perl backticks under the various flavors of unix will do the right thing with that redirection syntax. (And if I'm wrong, it's probably because you're using something I haven't seen yet, which is possible. ;)

As for running on windows, you could either make sure that "bash.exe" is installed in a common "PATH" directory, or else make sure that your script knows (and uses) the correct absolute path (e.g. "C:/gnu/bin/bash" or whatever); as BrowserUK noted above, just put bash at the beginning of the backtick command line.