Find a simple pseudo-static Nginx Rewrite solution

Ask for a simple pseudo static Nginx Rewrite such as http://www.a.com/a.php? The number behind id = 2id is variable & nbsp; I need to rewrite to & nbsp; http://s.a.com/a.php? Id = 2 access the http://www.a.com to find a simple pseudo static Nginx Rewrite
For example
Http://www.a.com/a.php? Id = 2 id followed by a variable

I need to rewrite
Http://s.a.com/a.php? Id = 2

Access http://www.a.com/a.php? Id = 2 is read http://s.a.com/a.php? Id = 2
Not redirection.

I am at www.a.com
Write in
Rewrite ^/a. php? Id = (. *) http://s.a.com/a.php? Id = $1 last;

Jump
How can I prevent him from redirecting? thank you.

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It doesn't seem to work.
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Clearly tell you. No. Unless used as a proxy