Judging from the available controls I would say no.
I have it inserting a comment for logged in users as the 3rd one in a discussion.
It inserts a different 3rd comment for guests.
Very flexible indeed but it's asking too much for it to find a specific post, even if it could there would be complications I don't care to think about right now.
You could have Nuggets automatically post the first comment in each discussion though.