Ahh, I was thinking (since you said forum/post page) that you didn't want it on the portal page...
to do this, you need to actually hack the portal template and insert code manually (in which case, I'd use a custom insert and the "external use" code so it's easy to update vs having just static content that you'd have to go in and edit manually)...
what you'd want to do is open templates/default/portal.tpl and at about line 3, insert the external use code for the appropriate custom island, it must use smarty capable php tags however (found on the external use link in the portal settings); it'd look similar to:
{php}
if (!defined('UBB_MAIN_PROGRAM')) define('UBB_MAIN_PROGRAM',1);
$style_side="";$tbopen="";$tbclose="";
echo "<table width=\"100%\">";
include("/home/undergroundnews/public_html/forum/languages/english/portal_islands.php");
include("/home/undergroundnews/public_html/forum/languages/english/generic.php");
include("/home/undergroundnews/public_html/forum/cache/gallery_island_34.php");
echo "</table>";
{/php}Your paths will definitely be different than mine, i posted this meerely as an example, the code will not work as a mere drop in, you must use your paths and indicate the proper custom island.
If you're adamat that you don't want to use a custom island, then you can just insert plain html in this area, however whenever you want to update it you'll have to hack the template.
also, be sure to clear your cache once you update.
