Or at least with the multi-quote tool. Suppose you want to address a set of N posts. Click the multi post button Please Register or Log in to view the hidden image! on the first N-1 post, making each selected multi-quote button turn red, Please Register or Log in to view the hidden image!. When you are down to the last post in the set, click the plain-old-vanilla quote button Please Register or Log in to view the hidden image! on this last post. Presto-chango, you have a "reply to thread" form with N quoted posts.
You can also press the multi-quote button on all N posts and then click the 'post reply' button down the bottom.