How can I exclude domains from the caching proxy?

[hilfubsi]

For example, I don't want Spotify (which I pay for) to get a free ride and fill up my cache with music. I'd rather cache useful stuff like apt packages etc.

How do I tell squid to not cache certain domains and their subdomains? I don't want a particular host to bypass the proxy and cache, and I want to use domain names rather than IPs.

Is there a way? Or can I edit the squid.conf file manually and add it there? The header in the file says not to.