functions.php

<?php

/**
 * Register Archive Sidebar
 *
 */
function be_register_archive_sidebar() {
	genesis_register_sidebar( array( 'name' => 'Archive Sidebar', 'id' => 'archive-sidebar' ) );
}
add_action( 'genesis_setup', 'be_register_archive_sidebar', 20 );

/**
 * Display Archive Sidebar
 *
 */
function be_archive_sidebar() {
	// Only adjust on archives
	if( ! ( is_archive() || is_404() ) )
		return;
	
	// Remove Genesis Sidebar
	remove_action( 'genesis_sidebar', 'genesis_do_sidebar' );
	
	// Remove Genesis Simple Sidebars sidebar
	if( function_exists( 'ss_do_sidebar' ) )
		remove_action( 'genesis_sidebar', 'ss_do_sidebar' );
		
	// Add my sidebar
	dynamic_sidebar( 'archive-sidebar' );
}
add_action( 'genesis_sidebar', 'be_archive_sidebar', 5 );