Jeremy,
The feature is meant to be used in the originating thread. However, you can click a quote (or multi-quote) button for any message you want, copy the resultant code and text, then paste it into a message anywhere else you want - this forum or even some other website. However, the code used to indicate the original location of the quoted message, including the little
graphic, will not work on another non-vBulletin forum. If it's a vBulletin forum (referring to the forum software), the graphic that forum uses will show and the link will lead to a thread and post with the same ID number on that forum, or to a 404 error (page not found).
But yes, you can copy and paste the quote to some other thread on the same forum. You might just want to copy a portion of text by highlighting it and press the keyboard combo, Ctrl+C, then go to another thread and paste the text into a message there by pressing Ctrl+V. Wrap the [quote][/quote] tags around it to finish formatting it in a quote box (or just use the old-school
" and
" punctuation).
Jim