***CORRECTED***
I don't know that editor, but using the already integrated TinyMCE and restricting it to Admin side, seems to me a good enough solution. You can achieve that just adding this line at the very bottom of your theme functions.php (take care not to leave blank lines after this):
<?php $is_admin = strstr("http://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]", osc_admin_base_url());
if (!$is_admin) osc_remove_hook('init', 'rich_edit_init'); ?>
Regards