When you say you want to create a facebook comment module - what exactly do you mean - are you trying to simply add FACEBOOK like type features to HTML - or are you trying to build a module to inject comments directly into facebook.

If you are trying to do the later - i would have a look at http://facebooksdk.net/ as the basis of the access tools - it helps greatly with making the open graph connections work correctly in asp.net.

We use it to integrate facebook features into some of our custom modules.

Westa