File management on a Windows Server 2003 NAS system

We are using Windows Server 2003 on a network-attached storage (NAS) drive system. We are also copying files to this NAS via external hard drives. We are having problems with these files not being assigned the correct ownership. They usually end up with a strange owner or administrator and not the user we want. A lot of times if any of these files are then moved between folders, they become locked. We then have to go onto the NAS and manually change the permissions to the correct user and assign full control. Is there a way to have a folder that, if you put any file into it, regardless of current ownership, it will update and apply the ownership of that folder?