You can modify tinymce-advanced a little bit. You should use different constant for pluging path than WP_PLUGIN_URL.

You could do something like that in the start of the file:
$plugpath = WP_PLUGIN_URL . ‘/tinymce-advanced/mce/’;
if(function_exists(“domain_mapping_post_content”))
$plugpath = domain_mapping_post_content($plugpath);

define(“REAL_PLUGPATH”, $plugpath);

then search and replace.