A reverse proxy issue

I have an enviroment as follows:

   PC(192.168.95.2) ------ReverseProxy(Run Nginx,192.168.95.1

and 192.168.1.1)---------------OA Server(192.168.1.100)

                                             ---------------Mail

Server(192.168.1.200)

  PC want to access oa server1 and mail server through reverse

proxy,My config is :

upstream OA {
    server  192.168.1.100;
}
upstream  MAIL {
    server  192.168.1.200;
}

server {
listen 80;
server_name 192.168.95.1;

    location  /oa/ {
           proxy_pass  http://OA/;
           proxy_set_header Host $host/oa;
           proxy_set_header X-Forwarded-For $remote_addr;
      }
   location  /mail/ {
        proxy_pass  http://MAIL/;
        proxy_set_header Host $host/mail;
       proxy_set_header X-Forwarded-For $remote_addr;
    }

PC access OA server by http://192.168.95.1/oa/, access Mail server by
http://192.168.95.1/mail/.
But content return from OA server include some URL:

  1. /abc/xxxx/…
    These urls will be http://192.168.95.1/abc/xxxx/… in
    PC,They can’t be proxy.
  2. http://192.168.1.100/efg/xxxx/
    These urls will be http://192.168.1.100/efg/xxxx/… in PC, but
    PC can’t access 192.168.1.100 directly.
  3. http://192.168.1.200/ghi/xxxx/
    These urls will be http:// 192.168.1.200/ghi/xxxx/… in PC,
    but PC can’t access 192.168.1.200 directly.
  4. https://192.168.1.100/opq/xxxxxx/
  5. https://192.168.1.200/rst/xxxxxx/
All above urls can't be access by PC, How to config my Nginx?

Thanks.

Posted at Nginx Forum:
http://forum.nginx.org/read.php?2,152568,152568#msg-152568

you have to use regex for the location 's

Who can tell me how to do it ?

Posted at Nginx Forum:
http://forum.nginx.org/read.php?2,152568,153162#msg-153162