git-archive for files changed in revision range

Hiya,

We have a small project that is being managed in a Git repository (MSysGit to be exact) - mostly for backups and so on. The project is a mod for the computer game Civilization 4. (Actually a mod of a mod, but still...) As such, to release the mod to other people to actually use the only thing that needs to be released is all of the files that have actually been changed. (The actual git repository contains ~700MB of files, the vast majority of which haven't changed since the initial import and so don't need to be downloaded by people).

I've managed to make it produce an archive that contains only the files that have changed by using a combination of git-archive and git-whatchanged, along with grep and sed, but it's kinda unwieldly. Is there a better way of doing this?

The command line I used was something like (This is mostly from memory):
git-archive --format=zip . `git-whatchanged <start>..HEAD --pretty=oneline 
  | grep '^:' | sed 's/^.*\t//'` > release.zip

To produce a zip containing all of the modified and added files for the revision range <start>..HEAD.