protected function getNestedConfig($field, $config)
	{
		$field = preg_split('(__([0-9]+)__)', substr($field, 11), -1, PREG_SPLIT_DELIM_CAPTURE);

		if (!isset($config[$field[0]])) {
			return null;
		}

		$fieldConfig =& $config[$field[0]];

		for ($i = 0; isset($field[$i]); $i += 2) {

			if (isset($field[$i + 1])) {
				if (!isset($fieldConfig['fields'])) {
					return null;
				}
				if (!isset($fieldConfig['fields'][$field[$i + 2]])) {
					return null;
				}
				$fieldConfig =& $fieldConfig['fields'][$field[$i + 2]];
			}
			else {
				return $fieldConfig;
			}

		}
	}