INT 21 - LANtastic - CREATE USER AUDIT ENTRY
        AX = 5FA7h
        DS:DX -> ASCIZ reason code (max 8 bytes)
        DS:SI -> ASCIZ variable reason string (max 128 bytes)
        ES:DI -> ASCIZ machine name in form "\\machine"
Return: CF clear if successful
        CF set on error
            AX = error code
Note:   you must be logged in to the specified server and have the "U"
          privilege to execute this call