How to throw mongoDB query, directly to mongoDB server?

[eluser]zacksyah[/eluser]
is there function to throw query mongoDB like this $this->db->query($query) because I want to create mongoDB executor in codeigniter so if I type this query like this db.users.find({age:33}) codeigniter throw that query directly to mongodb server. or is there another way? please help, thanks in advance