Making Patch .zip files

Hi All,

I can't believe I cannot find this anywhere on the net. I feel stupid
for asking it but here goes:
I want to create a .zip file that contains all the files that have
changed between two tags (say between tag "A" oldest to tag "B"
newest)  on a branch in CVS. So, I would like to create a folder
structure that contained ONLY the changed files between these two
tags. Then, I could zip this folder structure up that included only
the changed files, give it to someone, they could un-zip this on top
of  their older release copy of the code (for example, a release copy
released at tag "A") and be up to tag "B".  I can't find any way to do
this in CVS. All I can find is a lot of references to .patch files
that indicate what exact changes are in the files. That's great but
what do I do with that? I can't find anything that explains what use
a .patch file is.

Is there any way to call a checkout of just the changed files between
two tags?  Can CVS checkout a folder structure that contains just the
files that have changed between two tags?  What good is a .patch file
anyway? What would I do with it?

Thanks,