Append an 'open' command to the script. The value of this object should be real server port number or name, followed by a comma, and then the protocol (either tcp or udp), e.g. '80,tcp'. Only the port number or name, and tcp or udp should be set. The 'open ' characters will be automatically appended. Also a 'null terminator' (\0) will be automatically appended. The null terminator and the 'open ' characters will be counted as characters in the script.