You are using OpenVPN for accessing single resource on the remote network, and you do not want all of your traffic to be routed through VPN. To achieve this, add the following directives into OpenVPN client config:

route-nopull
route 192.168.2.0 255.255.255.0

In this example I am routing only 192.168.2.0/24 through VPN, and everything else will use my normal routes.