Gus Perez has posted the binary and source for a little utlity he has dubbed “ezClip”;

Back in the 7.0 days I wrote a little tool called ezClip. It’s sole purpose was to allow me to copy/paste files from one command prompt window to another. Our test tree can get pretty deep directory-wise and having to provide full paths to ‘copy’ was a pain and instead I often ended up starting up two explorers, one from each window, and then copying via the GUI. This tool made this process much more painless.

Check out his post here, and grab the utility from here