Wonder whether it's possible to organize/filter comments for certain names on a blog response.

For example I'd like to use Wordpress, Blogger, or Edublogs to create a blog for all intermediate classes to use in my school. However, I'd like to offer teachers the option of filtering comments (responses) to blogs for their classes only, and not have to ask them to search all comments to see their students responses. Anyone know if any of the above have this feature built in?