Forwarding incoming traffic through VPN

[exabyte]

One of our customers has offices in 2 different cities.
Both offices are connected with an openvpn tunnel.

Office 1 has WAN IP1, Office 2 has WAN IP2.
The customer has a web server in Office 1.
Is it possible to forward traffic on port 80 that goed to WAN IP2 through the VPN tunnel to the internal IP of the web server in Office 1?

I tried different rules, but no success this far.

Thanks in advance for any help.