Block a specific resource, not the entire website

I have a slackware server on LAN with dnsmasq, dhcp etc. There is also one windows vista computer connected to the network.

I want to block a specific file from one website on the entire LAN or if it's not possible just for one computer.

I thought it could be done with dnsmasq, but it blocks the entire website. I searched for solutions, but i only found that i can add "127.0.0.1 example.com" in host file somewere in system32 which is not too helpful.

About blocking for one computer. The browser is Firefox, but i don't want to install any addons.

I'd be grateful fo开发者_如何学编程r any advice on what I should look for or any simple script to write for that.

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The only way I can think of doing this is to require that the clients access the Internet through a proxy server, such as squid, that supports the ability to block specific pages.