selective proxy port forwarding on Apache httpd
This worked for me. Might be of some help for others.
<VirtualHost *:80> RewriteEngine on RewriteCond %{HTTP_HOST} ^blog\.example\.com RewriteRule ^(.*)$ http://www\.example\.com/blog/$1 [L] ProxyPreserveHost On ProxyPass /blog ! ProxyPass / http://localhost:9000/ ProxyPassReverse / http://localhost:9000/ ServerName example.com </VirtualHost>