I already fix it…
To make this you have to do this…
In index.php in my template, I added this code:
<?php $ppl=$ppl+1;
if ($ppl==1) include(“advertising.html”); ?>
just after the <p class=”postmetadata”> section, and before the <?php endwhile; ?> section. So now when the $ppl variable is equal to one, the advertising.html file is included, at other times, nothing is.
And the create your advertising.html with the info that you want and that is it!!!