proxying/redirecting after request has been rewritten

[i0n]

Hi everyone. 

I'm trying to get Nginx to run some Regex's on requests and send them to
another server block, returning the response headers from the second
server block. At the moment I get a 302 response status, how do I get
the headers from the second server block?

So as an example, I would like a request like:
http://nginxrouting.local/some/stuff/that/needs/to/be/removed/itemid=1234/more/stuff/topicid=1234
to be sent to
http://nginxrouting_destination.local/itemid=1234topicid=1234 returning
the headers from the new location

The server blocks look like this:

server {
	server_name nginxrouting.local;
	root /var/nginxrouting/public;

	location / {

		if ($request_uri ~* ".*(itemid=[0-9]*){1}.*") {
			set $itemid $1;
		}	
		if ($request_uri ~* ".*(topicid=[0-9]*){1}.*") {
			set $topicid $1;
		}	
		if ($request_uri ~* ".*(&type=RESOURCES){1}.*") {
			set $resources $1;
		}	

		rewrite ^
http://nginxrouting_destination.local/$itemid$topicid$resources?
redirect;
		add_header itemid $itemid;

	}

}

server {
	server_name nginxrouting_destination.local;
	root var/govuk/nginxrouting/public_destination;
	location / {
		add_header working yes;
		return 200;
	}
}

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,229458,229458#msg-229458