Comments on posts from specific categories

Is it possible to have this plugin to get comments from posts posted in specific categories only?

Then, it could be possible to have a widget for getting and showing comments on posts in category A in one sidebar and category B in another sidebar,

I am not a PHP coder (that is why I became a member here), but I hope this is a some ways? I am not afraid of putting a lot of code into my templates either. Yes, I have installed the comment and post indexer.