VPN (WG) to VPN (OpenVPN) forward


I'm trying to configure a VPN forwarding solution and I'm a bit lost. My OpenWRT router provides internet access to my LAN. I'm not forwarding my standard internet traffic through any VPN.

Nevertheless, I'd like to forward some traffic through an OpenVPN connection some of the time. The traffic could come from my LAN as well as from outside my LAN. I'm thinking to do so by configuring my OpenWRT device as a WireGuard peer "server". The idea is that all the traffic coming in through WireGuard should be forwarded (and masqueraded) through the OpenVPN connection. (I guess I could do this through SOCKS, but WG is easy and quick also for mobile phones.)

How exactly would I go about configuring this?

Thanks so much.