$re = '/value="(?<yourValue>.[^"]*)/m';
$str = '<input class="thatclass" style="border: 0px currentColor; border-image: none; text-align: center; font-weight: bold;" type="text" size="35" value="Ata Tata Baba [3834]">';
preg_match_all($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