[JKT]

If you watch my screen casts again, the cell doesn't have to be the absolute lowest level, it just can't be a section or sub-section heading. Any sections or sub-sections that don't have any levels lower than them can have figures input in their number columns. So structurally all you have to make sure is that you create new (sub-)section headings for your current content to take the role of the (sub-)total field for that (sub-)section.