Sticky post at a certain place beteen the posts

Im searching for a plugin whose able to make a post and set it at a certain place between the posts.

Example: i make a news post with an advertisement, i would like to have it placed between the 3th en 4th post and when i post a new post the posts just go down so the 2th and 3th post will be the 3th and 4th post on top and bottom of the advertisement.

I read something about Adhesive plugin, but since that website is down im not able to check it out, and do not know if that’s the software im searhcing for.

Thanks in advance