Your skin is different than mine so you will have to look carefully. in forum view > forumindextemplate find
<br />
<if test="hasannouncements:|:is_array( $announce_data ) AND count( $announce_data )">
<table class='ipb_table topic_list hover_rows' summary='{$this->lang->words['forum_topic_list']} "{$forum_data['name']}"' id='announcements'>
<foreach loop="announcements:$announce_data as $aid => $adata">
<tr class='row2 announcement' id='arow_{$adata['announce_id']}'>
<td>
<php>$_seoTitle = $adata['announce_seo_title'] ? $adata['announce_seo_title'] : "%%{$adata['announce_title']}%%";</php>
{parse replacement="t_announcement"}
<h4>
<a href="{parse url="showannouncement={$adata['announce_id']}&f={$forum_data['id']}" seotitle="{$_seoTitle}" template="showannouncement" base="public"}" title='{$this->lang->words['view_announcement']}'>{$adata['announce_title']}</a>
</h4>
<span class='desc'>{$this->lang->words['posted_by']} {parse template="userHoverCard" group="global" params="$adata"}
<if test="announcedates:|:$adata['announce_start'] AND $adata['announce_start'] != '--'">, {$adata['announce_start']}</if>
</span>
</td>
</tr>
</foreach>
</table>
<br />
</if>
copy and cut this from template and find
<script type='text/javascript'>
new ipb.Menu( $('forum_filter'), $('forum_filter_menucontent'), { stopClose: true } );
</script>
add the code copied after the above and add a header you can copy it from the pinned topics header for the word announcements..
Good Luck.