Hello.
Trying to write a rewrite rule that will transform this url
http://external_site.com/login?back_url=http%3A%2F%2Finternal_url%2F
to this one
http://external_site.com/login?back_url=http%3A%2F%2Fexternal_site.com%2F
I know I need to play with arguments and rewrite but I'm stuck.