automatic tag changes for news feeds in calibre?

[SDgirl]

Hello everyone,
I'm new to this forum but have been lurking for quite sometime trying to decide between the sony prs 505 and the kindle 2. I ended up getting the blue sony at fry's over the weekend

Anyway, I have a mac and downloaded calibre. I'm using the fetch news feature and have a few magazines/newspapers that automatically download every morning. Is there a way to automatically change the tags when it gets downloaded. For example, for the CNN news feed, the tags automatically assigned to it are "CNN, News". I would like for the tag to just be "CNN" each time, but don't want to go in and individually change it after each download. Is there a way to do this?

Thanks!