Map CSS, JS, image external links to internal resources

[eluser]Unknown[/eluser]
I have two domains external.com and internal.net. I developed CodeIgniter app in internal.net. I've relocated application and system folders from external.com to internal.net as described here .

Now I have a problem that css, js and image files are located at internal.net, but links are looking like as if they were at external.com. However these links don't map to real files. I tried .htaccess - no gain. How to overcome this?

[eluser]mackblack[/eluser]
Can you attach some of your code snippet? It would be beneficial in order to find out the solution.