Thanks for your help Styopa,

I was able to find modules installed on our current proxy with the following command, because we have a customize module.

:~# /usr/local/nginx/sbin/nginx -V
nginx version: nginx/0.7.67
built by gcc 4.4.3 (Ubuntu 4.4.3-4ubuntu5.1)
TLS SNI support enabled
configure arguments: --prefix=/usr/local/nginx --with-http_ssl_module --add-module=/home/ngx_http_cust_app_version_routing

I tried to redirect base on URL

for instance I tried:
Redirect ^/app2$ http://app2.server2.com;

but does not seem to be working, I can't find much in the logs. do you have any suggestions?

Thanks,
-Motty