codeigniter - Call a controller from a method -

Can we call an administrator and parse the controller with any value or data in one method? Assume that I have this method,

  function loader () {// some actions to call another controller}}   
 and that By law, I want you to call a controller named Welcome. Php which is located in / app / controller  i'v tried to do this but it does not work  
  function loader () {$ open = new welcome ();   
 It says that  class reception was not received   
 sorry for my bad english   
 
 
 Firstly you must include the file  
  include ('welcome.php');   
 Then, create an object.  
  function loader () {$ open = new welcome (); // If you want to call a method in an object $ open-i- MyWelcomeMethod (); }