Ok I got it! Thanks for your help. I did the following:
In function.php
// This will create your widget area
function search_widgets_init() {
register_sidebar(array(
'name' => 'Header Aside',
'id' => 'header-aside',
'before_widget' => '<li id="%1$s" class="widgetcontainer %2$s">',
'after_widget' => "</li>\n",
'before_title' => "<h3 class=\"widgettitle\">",
'after_title' => "</h3>\n",
));
}
add_action( 'init', 'search_widgets_init' );
// adding the widget area to your child theme
function my_header_widgets() {
if ( function_exists('dynamic_sidebar') && is_sidebar_active('header-aside') ) {
echo '<div id="header-aside" class="aside">'. "\n" . '<ul class="xoxo">' . "\n";
dynamic_sidebar('header-aside');
echo '' . "\n" . '</ul>'. "\n";
echo '' . "\n" . '</div><!-- #header-aside .aside -->'. "\n";
}
}
add_action('thematic_header', 'my_header_widgets', 8);
function remove_branding() {
remove_action('thematic_header','thematic_brandingopen',1);
}
add_action('init', 'remove_branding');
function my_brandingopen() { ?>
<div id="header_box">
<div id="branding">
<?php }
add_action('thematic_header','my_brandingopen',1);
/* add search form to header
*/
function add_searchbar(){
include (TEMPLATEPATH . '/searchform.php');
}
add_action('thematic_header','add_searchbar', 8);
In style.css:
#header_box {
clear: both;
margin: 0 auto;
overflow: hidden;
position: relative;
width: 960px;
}
/* Moves blog name & description to the left */
#branding {
float: left;
width: 620px;
margin: 0 0 0 10px;
padding:8px 0 1px;
}
/* Moves the new widgetized area to the right and levels it with #branding */
#header-aside {
float: right;
width: 300px;
padding: 88px 0 44px;
}
Thanks for your help!