Ok, so I added a custom vbcode "share"
[quote]<a href="file://{param}">{param}</a>[quote]
So now I just need to make this a no hassel thing just like typing in your favorite url. vBulletin automatically parses the text and puts the "url" tags around it for the person who posted (no extra work or knowlege of the vbcodes necessary).
I still think it has to do with the stuff in the functions.php, but correct me if I'm wrong.