Can Doctrine INDEXBY be used in the RawSql function? If so, where to place?

Question

Is it possible to have the Doctrine Collection INDEXBY feature used in RawSql? If so, how?

I'd like to index the collection returned by the following query on s.constant_name.

$q = new Doctrine_RawSql();
$q->select('{s.*}, {us.*}')
   ->from('User u 
           CROSS JOIN Setting s
           LEFT JOIN User_Setting us
           ON us.usr_auto_key = u.usr_auto_key 
           AND us.set_auto_key = s.set_auto_key')
   ->addComponent('us', 'User_Setting us')
   ->addComponent('u', 'us.User u')
   ->addComponent('s', 'us.Setting s')
   ->where('s.sct_auto_key = ? AND u.usr_auto_key = ?',array(SETTING_USER, $this->usr_auto_key));