creating p2p wcf chat application to communicate between 2 particular clients(private message).....

hi,
Iam exploring wcf.I have created a chat application using wcf in c#.net.It works properly but i want to add a feature where private chat between 2 clients must be allowed.When i send message all clients can view it.but what if i want to give a direct message to a particular client.Iam using netpeertcp.
According to the concept i think, i will have to create a new chat mesh between 2 clients required to pass message.I need to use pnrp tp resolve the addresses of clients so that i can identify the peer to chat with.
But i really dont knw how can i achieve this through code.iam new to wcf but know the concept as i went through number of msdn articles.how should i start the code?where should i write it?i just want a start n support so i can explore it further.
I really would be pleased n thankful if someone would help me in any way they can.waiting for a reply .
THANKS.
Mumtaz.