protected function notAlphaNumCount($parameter, $password)
    {
        $len = intval($parameter);
        if ($len) {
            $results = array(); // Not used but required
            $count   = strlen($password) - preg_match_all('/[0-9A-Za-z]/', $password, $results);
            if (($len > 0) && ($count < $len)) {
                $this->_addError(sprintf(
                        $this->translate->plural('should contain at least one non alphanumeric character', 'should contain at least %d non alphanumeric characters', $len),
                        $len));
            } elseif (($len < 0) && (($count > 0) || (null === $password))) {
                $this->_addError($this->translate->_('should not contain non alphanumeric characters'));
            }
        }
    }