I have an idea “the button” is the at the bottom of each post. I wonder if this mockup @tophee had in mind:
I went off on a tangent because this solution knocks the current “Reply” button out of the link box.
I feel it doesn’t really belong there anyway… I’m clicking "link to this article’ not “reply with quote”
I found the topic which is most relevant to my sidebar comment:
Solving the reply-as-linked-topic need would simplify the usage which is the heart of the current topic.