How to load a view for the error page?

[eluser]Aquillyne[/eluser]
[quote author="clooner" date="1212937664"]You could do a redirect in the error pages to a special "error" controller![/quote]

The problem with that would be that the final error page would not give a 404 error.

Furthermore it seems impossible to reference CI inside an error page. To redirect (and what's the point in doing in manually) I'd have to load the URL helper. But calling $this->load->helper("URL") doesn't work: load isn't a property of $this in the scope (not that I know what the scope is).

What I really want is to deliver a 404 error header with the error messages supplied by CodeIgniter to the /error pages, but to feed it into a view as usual with any other page.

Isn't there a way?