automatic change post category

Hi I wanted to know if there was a way of changing a category that a post belongs to automatickly.
I have a news website. I have 2 areas that displays the news. one displays headlines one displays general news. and both have separate categories. now I need somthing where when a new headline is written, the old headline should go into general news kategory. I know it’s complicated but can any one help is there a plugin that does this. any ideas guys