netstat will show you open ports/active connections/closing connections. If you do not have a direct connection to the system you are trying to find, then it will not help you. Chances are though if you already have a connection to some system, you already have the IP (or DNS name which is just as good).
I suggest you read up on the tool you want to use before you try and do something with it. You are not going to bang in a nail if you have fork in your hand
That and understand the arena you are playingin. In this case, the messenger protocol: http://www.hypothetic.org/docs/msn/index.php
Read that, and whatever else you google (And I do expect you to google for more
to learn as much as you can about MSN to find out how you can do what you want with it.
Eiither that or give up