Hello all,

I'm a total newbie Context user trying to do something that is apparently
way beyond me.  I'm trying to set up a conceptual three-column design grid.
The idea was to use the two columns on the right for body text, the column
on the left for margin paragraphs, and the full three-column spread for
headings.  The easiest way I could find to set such a thing up was this:

\setuplayout[backspace=3.083in,
    leftmargin=2.083in,
    leftmargindistance=.25in,
    width=4.417in,
    rightmargin=1in]

where "leftmargin" represents the leftmost column and "width" represents the
other two columns (plus gutter).  So far so good.

To get my heading to stretch across all three conceptual columns, I thought
I'd use something along the lines of:

\start
\startlocal
\setuplayout[...]
\stoplocal
\section{This heading was supposed to start at the left edge of the left
margin and wrap at the right edge of the text area}
\stop

where [...] would eliminate the left margin and margindistance and
re-allocate that space to the text width.
However, I haven't yet found any [...] that does the trick.

Whether my approach is basically right or totally wrong, I'd love to get
guidance on the best way to typeset a heading across both the margin and the
text area.  I'm aware that it's trivial to make section numbers appear in
the margin; this is not the solution I'm looking for, though.

Thanks for your help,
Aric