Language Monitor Query

I am writing a language monitor and an application on Win-XP to show the
status of the USB printer. Currently I am planning to get the printer status
from the port monitor and to send it to the application via shared memory.
What are the other responsibilities of a Language Monitor to work it
correctly. There are some calls to SetJob and SetPort APIs in the PjlMon
sample provided with DDK. Are these calls are sufficient for a Language
monitor to work correctly?

The USB printer, for which I am writing the language monitor, follows the
PJL standard but some of the status codes are not according to the PJL
standard. How will this affect to my language monitor and what changes I
need to do in PjlMon sample to make my LM work.

Please help..

Thanks,
Nitin