[Plugin: JournalPress] Overwrite an existing LJ post with JP content

Before discovering JournalPress, I was crossposting my entries manually. I would now like to connect the existing posts to the posts on WordPress so that every time I edit my WordPress Posts it overwrites the pre-existing post instead of creating a new post. Or at the very least, I would like to be able to manually delete the post that JP creates when I crosspost and edit the contents of the SQL database so that the next time I update the WordPress post JP will overwrite my pre-existing LJ post rather than look for the post that JP initially created. Otherwise I’m going to have a gazillion duplicate entries muddling up my journal and that’s not what I want. I can’t delete my old entries, since they have all the comments and those are the links people have been sharing. XD

Does that make sense?