Hook to generate a dynamic sitemap with “All in One SEO Pack” Plugin

This is the solution from Peter Baylies (Plugin Author)

add_filter( 'option_aioseop_options', 'itdge_sitemap_addl_pages' );

function itdge_sitemap_addl_pages( $option ) {
    if (   !empty( $option )
        && !empty( $option['modules'] )
        && !empty( $option['modules']['aiosp_sitemap_options'])
      ) {
        $my_sitemap_entries = Array(
        '/test1' => Array( 'prio' => '0.1', 'freq' => 'daily', 'mod' => '2014-04-01' ),
        '/test2' => Array( 'prio' => '0.3', 'freq' => 'weekly', 'mod' => '2014-03-02' )
        );
        if ( empty( $option['modules']['aiosp_sitemap_options']['aiosp_sitemap_addl_pages'] ) ) {
            $option['modules']['aiosp_sitemap_options']['aiosp_sitemap_addl_pages'] = Array();
        }
        foreach( $my_sitemap_entries as $k => $v ) {
            $option['modules']['aiosp_sitemap_options']['aiosp_sitemap_addl_pages'][$k] = $v;
        }
    }
    return $option;
}