WAL archiving from a standby backup strategy Postgresql 9.3

Hello
I am trying to figure out if wal archiving from a standby is possible and a viable option for a backup strategy on Postgresql 9.3. The idea is to be able to take regular base backups and wal archives from a standby server in a remote DR site. Unfortunately, the archive_command functionality is not available while the server is in standby_mode mode so I am wandering if the wal archiving could be done successfully using alternative ways like rsync, lsyncd etc. Does anyone tried to go this path and eventually share his experience.