Hide certain folders over the network

Hi all,

I am looking for a way to hide certain folders from general users but make them available to the department who made the folder.
The main folder is shared out over the network and there are 7 subfolders – I would like all users to see 2subfolders and the department to see all 7 subfolders.
Encrpytion is not an option as the department is sectioned into an NT\W2k group.
IS it possible at all?