You have to be a little industrious lol...
First, click "Quote" in the first post you want to quote. When it goes to the reply page, copy that text to the clipboard. Repeat as necessary, pasting and then re-copying until you have all the quotes text saved.
Then for the last post you want to quote, you can click on the quick reply link and check the box to quote that message, and then just paste in the saved quoted text into the quick reply. (Or obviously you can just paste everything into the regular reply box.)