I was successful in using fragment with drupal_goto, but when I use it AND query, I am not able to get the request parameters using $_GET from the query.
I can see the request parameters in the URL, but it returns NULL. The URL is constructed as http://mydrupalsite/?code=success#overlay=admin/vendor/auth-stripe.
I am attempting to use $_GET['code'] to get the parameter. I also tried $_REQUEST