[xsl] Lineheight conditional based on page position

["Cuzner Stephen P" <Stephen.P.Cuzner@xxxxxxx>]

I've got a request to modify the lineheight of a heading being set in a
fo:block based on whether the block falls at the top of a column or not.

If Chapter 1 starts at the top of the column I would want

<fo:block lineheight="18pt">Chapter 1</fo:block>

But if Chapter 1 starts in the middle of the column I would want

<fo:block lineheight="21pt">Chapter 1</fo:block>

I'm using AH Formatter V5.

I'd appreciate any ideas.

Steve Cuzner