INT 21 - Novell NetWare - QUEUE SERVICES - CHANGE TO CLIENT RIGHTS
        AH = E3h subfn 74h
        DS:SI -> request buffer (see below)
        ES:DI -> reply buffer (see below)
Return: AL = status (00h,96h,D0h,D1h,D5h,D9h) (see AH=E3h/SF=64h)
Desc:   temporarily assume the login identity of the client submitting the
          job being serviced
Notes:  this function is supported by Advanced NetWare 2.1+
        caller must be a job server which has obtained a job for servicing

Format of request buffer:
Offset  Size    Description
 00h    WORD    0007h (length of following data)
 02h    BYTE    74h (subfunction "Change To Client Rights")
 03h    DWORD   object ID of queue (big-endian)
 07h    WORD    job number (big-endian)

Format of reply buffer:
Offset  Size    Description
 00h    WORD    (call) 0000h (no results returned)