Paragraph space before - can styles apply it intelligently?

[timpani]

I'd like to set up heading styles with space before when the heading style follows body text but no space before at the top of a page or when following a previous heading.

For example:
Heading 1: 24 points before, except at top of page
Heading 2: 18 points before, except at top of page or following heading 1
Heading 3: 12 points before, except at top of page or following heading 2


etc...

I found a compatibility option that stops the space before setting from being applied at the top of the page, but does anyone know whether it's possible to suppress the space before based on the style of the previous paragraph please?

I'm using Word 2003.

Thanks!