Recognize text in message box by "Net send"
 

Dear all,

I am writing a simple message sending (and hopefully receiving) program by
"net send" command. The messages can be sent properly. The program also have
a send out history in a text box so that the sender can read what he has
sent.

Now I want that the program can recognise all the text from message box
(messenger) sent by other colleague and add the text to the history text
box, something like icq. Is there a way to do that (any plugin or script)?
Or can I send message directly to the machine which is running the program?

Thanks in advance