You can proxy your requests through HTTP using CONNECT method. This can help if you are only allowed to access outside world through HTTP proxy server.
Server has -proxy option allowing to listen on specified port and accept HTTP request. All of them will be treated as a CONNECT method switching to raw TCP mode. You can make POST request and server will anyway switch to raw TCP mode. You are not forced to use this option: any external HTTP proxy server can be used.
Client has -proxy option forcing it to connect to proxy and send CONNECT method. Optionally it can be authenticated on it using -proxy-auth HTTP Basic method.
$ govpn-client [...] -proto tcp \
-remote "$REMOTE_ADDR":1194 \
-proxy 192.168.55.1:8888 \
-proxy-auth mylogin:password