extract all files changed in a git commit

I need to make a patch for someone (they are not using git) - a zip of the files changed by a commit.

I thought something like

git archive --format=zip commitguid > myfiles.zip

but this extracts the entire thing, not just the changed files. Is there any way to do this? And to make it more complicated - is there any way of doing this with multiple commits (yes I should have branched before making the changes but that's hindsight)

EDIT

Based on @Amber solution below I can do this in 2 steps in Git Bash for windows with 7Zip installed in c:\data\progs.

git diff --name-only a-sha b-sha > tmp.txt
/C/data/progs/7za.exe a myzip.zip @tmp.txt