Bro, if I understood your question, you have one computer using socks. Now you want to install VPN into this same computer and use socks with vpn, same time... I believe for this, you just need to install the VPN client, and setup it. Since it's running with the IP of the VPN server, you just set up the socks into browser. And in your browser you will have SOCKs ip, and for other applications you will have VPN ip. When the VPN is running, it already hooks all sockets connections, so you socks connection will be made from VPN automatically... This is what I believe.