The Add Content to Page behavior does not allow you to create CMS Templates.
To Create a CMS Template Content area,, you need to use the CMS Admin Section.
the first part of the tutorial walsk through that step in the "Create the template" section.
you may find the Video version of this tutorial more helpful:
http://www.youtube.com/watch?v=kbplAlzNexI&list=PL21CA2EF37DE22B2C&index=2