Hi ghoshy,
HTML does not define tags for printing, and CSS is very limited.
Here is the current standard for CSS2, paged media:
Magins, etc need to be defined in a style sheet, and can't be defined through inline styles. Which means the editor won't be able to do this for you. You'll need to create your own stylesheet for your printable areas, then set the CSS Name properties of your div's.
Ady