Logon Screen Saver - how to make it move?

OK I know how to change the logon screen saver. I have a small batch
file to do it as part of our install process and it works. What I
would like to do is use our university logo and have it move around
the screen.

How do I have my scr file move around the screen like logon.scr ?


---blank-scr.bat---
:: Install a blank screen saver

@echo off
copy /y %Z%\packages\blank.scr %WinDir%\system32

:: Change logo screenscaver from logon.scr to blank.scr
reg add "HKU\.DEFAULT\Control Panel\Desktop" /v SCRNSAVE.EXE /t REG_SZ
/d blank.scr /f nul

:: Change blanking time to 60 seconds
reg add "HKU\.DEFAULT\Control Panel\Desktop" /v ScreenSaveTimeOut /t
REG_SZ /d 60 /f nul
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