Making GtkTreeViewColumn shrink as other columns to it's left grow.

[kcirtap lavabit com]

Hi, I've got a few resizable GtkTreeViewColumns, a column that has it's
"expand" property set as TRUE, and finally a column that isn't resizable.

I'd like to make it so that making one of the resizable columns larger (by
manually resizing it) forces the "expand" column to the right of said
column-being-resized to shrink accordingly. Kind of like what happens when
I manually shrink the GtkPaned that the GtkTreeView with these columns is
packed into.

Right now, when I make one of the resizable columns larger, it simply
makes the GtkTreeView wider (and causes the scrolled window it's in to
show it's horizontal scroll bar) and the columns to the right of the
column being resized do not shrink.

Is this possible? I've tried a few different things, none seem to work...
perhaps I missed something in the API docs?

Thanks.