such as :
Client(192.168.1.101) want visit http://192.168.1.201:9000/myfile example,and need visit other ports.
but client must use proxy to visit. Nginx is the proxyer!

Nginx proxy running on 192.168.1.202 and listen at port 8080 .
I use '''proxy_pass $scheme://$host$request_uri;''' to make proxy,but I get http-502 when I use this proxy-server.
Becase nginx use the default port 80 to proxy:
| request = http://192.168.1.201:9000/myfile
| proxy-server = 192.168.1.202 8080
| proxy-to = http://192.168.1.201:80/myfile
There are only $remote_port and $server_port on nginx-variables: http://wiki.nginx.org/HttpCoreModule#Variables

If I just want visit port 9000 on 192.168.1.201,I can write by '''proxy_pass $scheme://$host:9000$request_uri;'''
But it's not a good idea ,and there are some other port to use.

How can I do ?