The RSS feed for "hot questions" for on our main site is:
You don't need to parse or filter from the feed for all network questions. Just use the site specific hot questions feed and change the site url as needed.
Alternatively, you can use a third-party solution like FeedRinse to create a custom filtered feed.
Here is an example of the hot network questions feed with only questions from CodeGolf.SE:
The filter criteria was simple, look at the
<title>, if "codegolf.stackexchange.com" is in the title, show it in the feed, otherwise ignore it.
You do things with this like combining it with some service like IF This Then That (IFTTT)'s SMS channel to send you a SMS text alert every time a hot question appears on the list that is from code golf.