File Permission

[Adam Davis]

I'm trying to create a file in another user's directory that that user can
read but can't delete.  Simply chowning it to root and chmoding it 744,
444, anything seems to fail.  The user is able to delete the file despite
the lack of write permissions.

If I take away the user's ownership of the directory, the user can't
delete the files.  But it's important that the user own the directory.

Any way to accomplish this?

~Adam Davis