this sounds like you want a site-to-site setup, which is perfectly well possible. Read the OpenVPN HOWTO for details on how to set this up.
On site A, I'd do something like
openvpn --genkey secret.key
Transfer this key to site B.
Then run on site A:
openvpn --dev tun --proto udp --port 1194 --secret secret.key --ifconfig 10.200.0.1 10.200.0.2 --route 192.168.2.0 255.255.255.0
On site B:
openvpn --dev tun --proto udp --port 1194 --secret secret.key --ifconfig 10.200.0.2 10.200.0.1 --route 192.168.1.0 255.255.255.0 --remote <siteA IP>
After that you need to tell the network at site A that the network 192.168.2.0/24 can be found via 192.168.1.1
Vice versa, you need to tell the network at site B that the network 192.168.1.0/24 ca ben found via 192.168.2.1
HTH,
JJK
