can not rewrite url

Hi

I am trying to rewrite url the ends with “222” to url that ends with “34” in wordpress.
e.g. http://www.example.com/author=222 —> e.g. http://www.example.com/author=34
I have added these lines to my function.php:

add_action( 'init', 'mydid_add_rewrite_rules' );
function mydid_add_rewrite_rules() {
   global $wp_rewrite;
   add_rewrite_rule( '222', '34','top');
   $wp_rewrite->flush_rules();
}

However, that doe not work. the link with “34” works, but with the “222” doe not. I also checked with monkeyman-rewrite-analyzer and it seems that the rewrite rule is not inserted. Why? I AM flushing…

Thanks a lot.