LoadModule proxy_module modules/mod_proxy.so
LoadModule proxy_balancer_module modules/mod_proxy_balancer.so
LoadModule proxy_ftp_module modules/mod_proxy_ftp.so
LoadModule proxy_http_module modules/mod_proxy_http.so
LoadModule proxy_ajp_module modules/mod_proxy_ajp.so
LoadModule proxy_connect_module modules/mod_proxy_connect.so

RewriteEngine on

RewriteCond %{HTTP_HOST} ^somesite.gov.ar$ [OR]
RewriteCond %{HTTP_HOST} ^www.somesite.gov.ar$ [OR]
RewriteCond %{HTTP_HOST} ^somesite.gob.ar$
RewriteRule (.*) http://www.somesite.gob.ar$1 [R=301,L]

ProxyRequests On

ProxyPass / http://xxx.xxx.xxx.xxx/
ProxyPassReverse / http://xxx.xxx.xxx.xxx/

Server version: Apache/2.4.6 (CentOS)
Server built: Jan 12 2015 13:22:31
Server's Module Magic Number: 20120211:23
Server loaded: APR 1.4.8, APR-UTIL 1.5.2
Compiled using: APR 1.4.8, APR-UTIL 1.5.2
Architecture: 64-bit
Server MPM: prefork
threaded: no
forked: yes (variable process count)