Update files based on a tag without removing others?

[Peter Loron]

We have a situation where we have a large tree of files checked out. Each day, a small subset of those files are tagged. I was hoping I could revert a tagged set of files easily with one update or checkout command like this:

cvs update -r prop_20071022 <moduleroot>

...what winds up happening is that the files with the given tag are present, but everything else is deleted. What I'd like to be able to do is that operation, but keep all the other files unmodified. I know can can go through the list of files with a given tag, and issue an update command for each file, specifying the tag, but that's a hassle.

Any insights other than "tag the whole tree not just a few files"?

Thanks!

-Pete