$re = '/name="(.{6})" id=".{6}" value="(.{43})"/m';
$str = '<input type="hidden" name="Yw55vQ" id="Yw55vQ" value="06kcaY4_oXjDY-CB5lvTyk6edgWgn6qEuo2mMFvDfmE" />';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php