Group Policy in windows 2000 server

Dear All

We have windows 2000 server and windows xp clients in our office. This is server mainly used as file server all the users will access their respective share folder in the server to open their data. I want to restrict users copying/saving their data in their local disk and at the same time they should be able to open one particular folder which is already created in their local disk. I understood that in Group policy we can do lot. Can someone tell me how to accomplish this and where exactly the option is!!

Regards
Sakthi