An *.ocb-File is just a *.zip-File with the content of the %appdata%\Roaming\GPSoftware\Directory Opus folder.
To excute a DOpus-command from outside DOPus you can use dopusrt.exe /cmd:
"C:\Program Files\GPSoftware\Directory Opus\dopusrt.exe" /cmd Prefs Backup=all TO "D:\Mine\Backups\Opus\Opus Backup on {date|yyyy-MM-dd}"