Plugin for ad_showthread_firstpost, which hook Localtion?

[fabioski]

Ah for a similar plugin which has to working in HEADER template?
Which hook location have I to choose?
I try with showthread_complete and showthread_getinfo but it doesn't work

--------------- Added [DATE]1221770174[/DATE] at [TIME]1221770174[/TIME] ---------------

The plug-in generate correctly the variable:
$testo_adv_header .= "$row_adv_header[adv_text]";
and I stamp it on site correctly:
echo "$testo_adv_header";

But in the template the variable does not appear!
<td>$testo_adv_header</td>
</tr>
</table>

--------------- Added [DATE]1221816017[/DATE] at [TIME]1221816017[/TIME] ---------------

And for footer template?