I've several cad project in a lan shared folder. Now they are accessible from the technical office computers and they can work on them, but also copy them on private drives or delete them from the server. I'd like to find a way or a software that permit them still to work on them, save changes, but that deny permission to copy or delete them. They are shared on a zyxel nas. One or 2 pc instead must have the total access also for copy and delete them.