can you make comment templates too?

Hi,
I made a category template to integrate Postratings to a certain category. Unfortunately, the rating doesn’t display in the comments page of the posts. The developer said that if my theme has a comments.php file I might have to put the Postratings code there too.
My question is: since I made a category template for this, can I also make a special comment template with the rating that will be called only by this category?
Also, If anyone has an idea of where in the comment.php code I should put the rating, thanks for letting me know.