how to overwrite a old post with WP?

So i want to fetch the rss of someelses forum and automatically post the threads on my blog. BUT...because the thread title will always be the same, i will get the same article titles each time someone replys in that thread.

Is there a way that my old post of that thread gets deleted and the new thread/post will stay when the rss feed gets fetched?

Hopefully someone actually understands what i am saying?......ahahhaha

 

Search for delete duplicate post plugin. That might do the trick.

 

Not being rude, but i need to know how i can fetch the rss of a forum that will pull the thread with all the posts in it each time is get renewed?
Posted via Mobile Device