MouGetNumQueEl

typedef struct _MOUQUEINFO {   /* mouqi */
  USHORT cEvents;              /* current number of event queue elements */
  USHORT cmaxEvents;           /* MaxNumQueElements value */
} MOUQUEINFO;

#define INCL_MOU

USHORT  rc = MouGetNumQueEl(QueDataRecord, DeviceHandle);

PMOUQUEINFO      QueDataRecord; /* Ptr to 2-word structure */
HMOU             DeviceHandle;  /* Mouse device handle */

USHORT           rc;            /* return code */