One of the ways is to use a script for your FTP. I don't know if it is compatible with ncftp, but it works with ftp. The scripting help is present in ftp and netrc man pages.
I have a file abc.txt in my web site ftp.aief.net (/tmp/abc.txt)
I want to change the access privilage of the file abc.txt to 777 from my local machine.
I require a single command line to do the above inorder to put the command in crontab.