I've written a simple Windows app to help debug/craft HTTP headers. It's for the kind of thing you'd do trivially on Unix using netcat, but which is strangely hard on Windows. People say that Unix is a developers' OS and Windows isn't. They have clearly never used Windows. Windows makes you develop all your tools yourself.
It's very simple, you write your HTTP headers on the left and press 'go', and the response headers are printed verbatim onto the right panel. There's also a more human friendly summary under the 'Summary' tab which will probably pull out the stuff that you're interested in.
Code is on GitHub, feel free to modify.