Description: Append an 'nsend' command to the script. The 'nsend' command is used to append additional content to the packet generated by the 'bsend' command when the desired 'bsend' content is more than 255 characters. The set value of this object should be the exact characters to be appended. The 'nsend ' characters will be automatically appended. Also a 'null terminator' (\0) will be automatically appended. The null terminator and the 'nsend ' characters will be counted as characters in the script.