Redirect all browser traffic to website x

Hello everyone,

I need to write a shell script, that redirects all traffic in your browser to a website x.
That means:

1. User sends a request to load website "www-somerandomwebsite-com"
2. the script redirects the request to a local file that is stored on the hard drive
3. User will always be redirected to website x


If someone could give me a hint on how to start with this script, I would be deeply thankful.
Thanks in advance.