When using REG.EXE (built into Windows XP and Windows Server 2003, or from the Windows 2000 Support Tools) to add or modify a registry data value, you must use the escape character (\) when your data is encapsulated in quote marks.

Example

To set a data value equal to
     "%UserProfile%\Local Settings\Application Data\Microsoft\Windows NT\NTBackup\data" "%1"
the text after the /d switch should be:
 "\"^%UserProfile^%\Local Settings\Application Data\Microsoft\Windows NT\NTBackup\data\" \"%1\""