Thanks Jang
I thought the whole idea with this Framemaker Scripting was "You can write a script to do anything you can do in the FrameMaker GUI" ... i.e. if you can click on it, you can script it! Thanks how the seminars sell it. Maybe they're being a bit optimistic 
I'm having a rummage in the FDK 11 documents too... there is a "what's new in FM11" section, but I don't see anything mentioned for that Publish command.
Basically, what my manager has said they would like to happen is:
I check my frameMaker files into their software build system, and we have a script to auto-generate .chm files for the HTML Help.
I thought I'd be able to do this if I could write a simple script which basically is just a macro of be opening a book and clicking File > Publish... ?