closing open files on a network

here's the problem, I need a way to close all open files for everyone except Administrator on Win2K Server with clients of Win2K Pro and Win98. Time restriction are set but it doesn't close the open files of the users (in WinNT it would close the open files, I miss NT :( ). I can close all the open files on the server with this command, but of course all files means Administrator as well. Policies have been tried as well but it doesn't work good, not sure if it's the way it's set up or the fact that there are Win98 clients in the mix. Upgrading them all the Win2K is not something I wish to partake at the present time.

Look at the NET FILE and NET SESSION commands.