I have the same question that Dragos asked here
"...Hi! I'm developing an application which hosts an web browser control. I'm getting access to it through IWebBrowser2 interface. Is there any way to have access programatically to the responses header..."
The solution (from 2003) seems to be using an passthrough Asynchronous Pluggable Protocol (APP) handlers. The solution presented here was written in C++/ATL so I was wondering if there is an c# version of this?
Note that I'm already able to get the cookie values from IWebBrowser2 (and WatiN), the issue is getting the raw headers values