Insert advertising tags ahead of first unread post

[weinstoc]

Is there a hook I can used to insert an advertising block ahead of the first unread post in a thread. (That is, when a user clicks on the down arrow to take him to the first unread post, he sees the ad ahead of the post?)

How can I accomplish this?

Thanks

[MarkFL]

What do your URLs look like in this case? Is there something like:

?p=xxxx

in the URL, indicating the id of the post?

[weinstoc]

Here's an example:

https://forumserver.twoplustwo.com/55/about-forums/2-2-most-negative-forum-internet-1714579-new/

The URL difference is the -new on the end.