How to route vpn through proxy?
Solution 1:
Read the official manual.
You can launch openvpn in the next manner:
# openvpn --config config.file --http-proxy 127.0.0.1 3128
However, http-proxy doesn't support UDP, probably, you can do this only with TCP vpn.
But there is --socks-proxy option for openvpn, you can use socks5 instead of http-proxy, socks5 do both UDP and TCP.