separators for HTML_QuickForm_date elements

Hi, i saw a lot of threads about groups and separators but i could find a answer to that : can we set customized separators for HTML_QuickForm_date's elements ? As it inherits from HTML_QuickForm_group, i thought i could set the '_separator' property, as it works for a group created with 'addGroup()'. i mean for ex :

/        $txtElm1=&HTML_QuickForm::createElement('text', 'nombre1', 'Nombre 1'.':', array('size'=>30, 'maxlength'=>100));
       $txtElm2=&HTML_QuickForm::createElement('text', 'nombre2', 'Nombre 2'.':', array('size'=>30, 'maxlength'=>100));
       $txtElm3=&HTML_QuickForm::createElement('text', 'nombre3', 'Nombre 3'.':', array('size'=>30, 'maxlength'=>100));
       $grupoTexto = &$this->addGroup(array($txtElm1,$txtElm2,$txtElm3),'GrupoTexto','label grupo :','-');

$grupoTexto->_separator=array('-','-'); / This works fine. But if i try it for a HTML_QuickForm_date it has no effect :

/    $dateFrom = new HTML_QuickForm_date('dateFrom','Fecha', array('language'=>'es','format'=>'dFYHi'));

$dateFrom->_separator=array('','','@','h'); $this->addElement($dateFrom); /Any idea ? Thanks.