Does this site cover what you want?:
"Customize Your Screen Savers
While I was working as an MCSE and systems engineer for Sarcom, a user at a client site requested that I set up a screen saver on every desktop. (Users did not have access to Display in Control Panel.) I wrote a system policies template to implement a standard screen saver. Listing 2 contains an excerpt from this template. (You can find the entire script on Windows NT Magazine's Web site at
http://www.winntmag.com. Enter 3799 in the instaNT Doc text box.)
This template lets you select and customize any standard Windows NT screen saver. The interface is simple. The Screen Saver tab in Display provides options for setting up the screen saver. You select the screen saver you want to run (under Settings, you can customize each screen saver), timeout period, whether to make the screen saver active, and whether to make it secure. I recommend that you try the screen saver on a desktop before you implement the policy settings".
Article