How to load another language to controller

[eluser]shinokada[/eluser]
I want to have Norwegian for the front-end and English for the back-end.

I have two controllers for these.

Now I set $config['language'] = "norwegian"; in applications/config/config.php.

But this makes the back-end in Norwegian.

How can I set up $config['language']= "english"; for the back-end?

How can I add this to the back-end controller?

Thanks in advance.