[EvilLS1]

Attached are one template mod (Quote Selected) and one hack (Quick Quote III).

The Quote Selected mod does exactly what you requested. It adds a button under your quick reply box and when you highlight text with your mouse & click the button it'll insert it into your QR box. The known limitations are that it doesn't work with the wysiwyg toolbar or require click for QR enabled and it only works with internet explorer. But when those options are enabled or the user isn't using an IE browser the button won't be displayed.

The Quick Quote hack adds a checkbox to each postbit. When the checkbox is ticked it instanly inserts the text from the post into the QR box. You can also quote multiple posts with it. However, to use it "Require Click for Quick Reply" must be set to no. Also, it does not work when the WYSIWYG quick reply toolbar is enabled. You can turn it on and off in the admincp under vboptions.