There's that little multi-quote button after each post, and it looks just so dern handy, but I can't figure out how it works! I searched the FAQ and found my answer. I thought the multi-quote button was what people used when posting little quotes from one piece... you know, multiple quotes? Oops. My bad.
When in doubt, search FAQ! Are you talking about what i did just now? If so thats easy. You just have to pick what parts of the post you want to reply to and put Quote tags around them. This is made easy by highlighting the chosen text and going up to the Quote button. It will automatically put them into place. Of course you may need to delete both the already existing Quote tags. Does that make sense?