How can i get packet tracking from a website through C#

Question

Hi,

I'm looking for help in order to solve that problem :

I'm currently developing a C# application for Windows Phone 8.
I want that application to be able to get packet tracking status from the official tracking website by simply sending the packet number.

For example I want to be able to get that kind of information : I send 81645X654Z -> and i get "Packet has been delivered".

The webpage is http://www.colissimo.fr/portail_colissimo/suivre.do
What is .DO ?

I've looked into the HTML source code of the page and I didn't really find the code responsible for delivering the packet delivery status...

Could someone please help me, this project is really important to me I really need to understand about communicating between C# app / websites.

Thanks in advance :)