This is a new feature in version 6.20.
There is a new snippet, @New, which is used to create a new snippet. When invoked, it displays a form that looks like this:
When you have filled in the Snippet Keyword, you will be able to create the new snippet. The PRG will be saved and opened at the place where you will want to add your own code for the snippet.
Note that you should also modify the function <PublishHelp> so that the @Help screen displays the syntax and description of your snippet.