Searching for a Announcement plugin with RSS support

Hi there, i’m searching for a announcement plugin which can update RSS channel.

Time to time i make an updates of my posts, i add new software versions, add new attachments, and i want to inform my visitors about that fact. I think that RSS is a good way to do that, will be super if there is a way to add a temporary post to RSS without publishing it on blog. I searched for announcement plugins but none of them supports RSS. Can you help me with this? Maybe there is some simple trick to that?

Thanks!