[abc] Will find any a or b or c character [^abc] Will find any character that is not a or b or c [a-z] Will find every letter in the alphabet \w Will find any "word" character A-Z a-z 0-9 _ \W Will find any non "word" character eg.
Set it to "Download all automatically" stop the torrents that start, then when new torrents are added to the feed they will download automatically.
If you want to download only specific releases, there are two ways to do that.
The simpler method is to right click on the relevant release in the list and choose "Add to favorites." This will add it to your Favorites list and bring up the RSS Downloader dialog for further editing of your favorite.
flexget is a little tool that reads RSS feeds and downloads certain torrent files to your watch directory, read the flexget article to set it up.