Using another domain to host everything in assets

Hi All,

I need to host my assets folder on another domain ( on the same server ) to reduce the number of http requests to the main domain, how would I go about this in the config files etc.

IE: all CSS and JavaScript can be called via direct links, however I need to know how to do the images and files from within the wysiwyg and file manager.

Thanks

EDIT: Also how can I protect this domain ( will only be used for that ) as I only want the main domain to be able to access it.

Cheers