Actually, it is a little different, but not much. You can do this easily enough if your news providers or aggregators allow you to build your own “feed” via a search. Yahoo news does this.
Just go to http://news.yahoo.com, and look down the page in the right-hand column till you find “News Services”, and beneath that you will find “News Via RSS”. Visit that link and you will find lots of instructions, and a search box where you can build your own “customized” RSS feed. Take the resulting URL, plug it into a “newsfeeds” item created via the Joomla newsfeeds component, and publish it… You are done!
Works similar in other services where you can “build your own feed”. Once you have the URL, you are home free!.