INT 2F U - NETWORK REDIRECTOR - SEEK FROM END OF REMOTE FILE
        AX = 1121h
        CX:DX = offset (in bytes) from end
        ES:DI -> SFT
            SFT DPB field -> DPB of drive with file
        SS = DOS DS
Return: CF set on error
            AL = DOS error code (see INT 21/AH=59h)
        CF clear if successful
            DX:AX = new file position
Note:   called by DOS 3.1+ kernel
SeeAlso: INT 21/AH=42h