regestering a filter device driver !?

 
regestering a filter device driver !?

#define FILE_DEVICE_RECO 0x00009000

#define RECO_MULDRV   (ULONG) CTL_CODE( FILE_DEVICE_RECO, 0x00,
METHOD_BUFFERED, FILE_ANY_ACCESS )

where am i suppose to register this number  0x00009000
that is if I should, or from where can I take numbers that are not
occupied
by another device driver and also register mine.