Problems with group policy ADM template

First a little back story... our network security guy has asked that we create a group policy that disables the processing of the autorun.inf files found on many CD's and other media.  He still wants the autoplay feature to work (music, movies, etc).

He found this http://windowssecrets.com/2007/11/08/02-One-quick-trick-prevents-AutoRun-attacks and sent it to me referencing the REG script below

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\IniFileMapping\Autorun.inf]
@="@SYS:DoesNotExist"

Now my task is to adapt that into an ADM file and create a GPO to configure the (Default) value in the HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\IniFileMapping\Autorun.inf

I have created the ADM file (shown below) and am able to import it with no problems, however when I try to apply the policy (gpupdate /force) I get the following two event messages

Event Type:      Error
Event Source:      Userenv
Event Category:      None
Event ID:      1020
Date:            5/14/2008
Time:            1:03:59 PM
User:            NT AUTHORITY\SYSTEM
Computer:      
Description:
Windows cannot create registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\IniFileMapping\Autorun.inf. (The parameter is incorrect. ).

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.


Event Type:      Error
Event Source:      Userenv
Event Category:      None
Event ID:      1096
Date:            5/14/2008
Time:            1:03:59 PM
User:            NT AUTHORITY\SYSTEM
Computer:      
Description:
Windows cannot access the registry policy file, \\***.net\SysVol\daiglobal.net\Policies\{D28A0160-BE9F-478B-B4B6-BC4790ABDA02}\Machine\registry.pol. (The parameter is incorrect. ).

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.


I'm assuming that this is because the VALUEON keyword in the ADM file is expecting a numeric value and I am giving it a text string.  So basicaly what I need to know is how to get the (Default) value set to "@SYS:DoesNotExist"

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CLASS MACHINE
 
CATEGORY "Auto Run"
	KEYNAME "SOFTWARE\Microsoft\Windows NT\CurrentVersion\IniFileMapping\Autorun.inf"
	POLICY "Disable autorun.inf"
		EXPLAIN !!AutoRun
		VALUENAME ""
		VALUEON "@SYS:DoesNotExist" 		
	END POLICY 
END CATEGORY
 
[strings]
AutoRun="Sets the value of (Default) to "@SYS:DoesNotExist" to disable processing the autorun.inf files."