Not quite sure what you're getting at. $cool has some value that you want to replace "Advanced" with in the $html string? Or you want $cool to equal whatever was matched?
In the first case, using preg_replace() instead of preg_match() will do it for you.
In the second, you'll want to use a third argument to preg_match() to store the match; call it $matches and the bit you want will be in $matches[0].