You will have to add a route for each function in your controller.
$route['admin/company/addNew'] ='company/addNew';
$route['admin/company/process'] ='company/process';
It's very annoying. Better, create a folder "admin" inside your "controllers" folder. Put the controller on the folder. Thus you can access your controller with the URL "localhost/admin/company" and all the methods without rerouting.
If it doesn't work at first, create a controller inside "admin" folder with the same name you'll find in your routes file (default_controller).