Inserting post just under the OP of a thread I created?

Is there a way to add a post just beneath the OP? Is that something a mod can do?

I don't think so, if you're the OP, you can just edit the thread post.

I had a mod answer my question. No, they can't.
The reason why I wanted a separate post was to avoid clutter in the OP (kinda how XBLA Deal of Week thread does). But oh well, I'll just remember to immediately put up a placeholder post when and if I remake the thread months from now.