I don't think you can - at least not in the way that you were hoping for. You would either have to build the query string yourself and execute it , or seek out or create a wrapper that supports that functionality. The one I use:
$id = 5;
$baz = 'shazam';
$select = $db->select()->from('bar','foo')
->where('id = ?', $id)
->where('baz = ?', $baz); // Zend_Db_Select will properly quote stuff for you
print_r($select->__toString()); // prints SELECT `bar`.`foo` FROM `bar` WHERE (id = 5) AND (baz = 'shazam')
Hope it helps!!