XF 1.5 Template conditional to target last post on a page

[SpecialK]

I need to show some content inside the last post of each page of a thread. What is the best way to target this using the XF conditionals? Specifically, I need to show the content:

In the last post of the page
IF the PAGE has more than 16 posts on it

So if a thread has only 8 posts on the last page, no content there, but on the previous page, it would have content (Because previous page would have 20 posts on it)

 

[upnet]

Here are the ad templates. https://xenforo.com/community/resources/visual-list-of-ad-locations.1383/
You could use the template ad_message_body or perhaps ad_message_below

Try something like:

<xen:if is="{$post.position} % {$xenOptions.messagesPerPage} == 16"/>
content
</xen:if>