Yes, I tried to guess what would open a chapter and found out that <alt>+<P>[c] = lyx code...
Sorry, I have to tell you: <alt>+<P>[0] = Part, [1] = Chapter, [2] = Section, [3] = SubSection, etc.<alt>+<P><*>[0] = Part*, [1] = Chapter*, [2] = Section*, [3] = SubSection*, etc.
Now I'm feeling nauseous...
Sorry. Vincent