Ok, in your fetch folder open
posts.php
Find
Code:$CFG['posts_hide_normal'] = false;
Replace with
Code:$CFG['posts_hide_normal'] = true;
Now normal posts won't be displayed.
By setting the option below to
false you make it display stickies.
Code:$CFG['posts_hide_sticky'] = false;
By setting the announcements option to true you hide the announcements and thereby force the page only to pull sticky threads.
Code:$CFG['posts_hide_announcements'] = true;
What I suggest you do is use stickies to determine front page threads, then set normal to true, announcements to true and sticky to false.
Now you can determine a front page topic from the posting page by making it sticky.