How To enable the "add ftp publishing" function to the Default Web Site using scripting commands in Win7

I'm currently trying to add ftp publishing to the Default Web Site in IIS Management for Win7 without using the GUI.  Some sort of scripting command such as powershell, Appcmd or C# directions would be appreciated.  Pretty new to many of the IIS command set so may have follow up questions.

Thank you in advance!

Daniel