Don't do that, pretty dangerous if people can just embed anything, but
Edit: I've only used MyBB once, can't remember very well, but it uses the preg_replace() function I think; I'm pretty sure it adds this automatically, but you may have to do add / and /, like this
Code:
\[4shared\](.*?)\[\/4shared\]
<embed src="$1" width="470" height="320" allowfullscreen="true" allowscriptaccess="always"></embed>Edit: I've only used MyBB once, can't remember very well, but it uses the preg_replace() function I think; I'm pretty sure it adds this automatically, but you may have to do add / and /, like this
Code:
/\[4shared\](.*?)\[\/4shared\]/