narrow with mode?

[David Abrahams]

Hi All,

I often find myself wanting to work on a region of a buffer in a
different mode from the current one.  For example, I'd like to use
markdown-mode on the body of a weblogger.el blog entry, and then I'd
further like to use c++-mode (or whatever) on code snippets within that
entry.  So I'd like to first narrow the body of the entry into markdown
mode, then narrow again to c++-mode, then pop back out to markdown mode
on the whole body, and finally out to weblogger-entry-mode on the whole
buffer.  

This seems like it must be an incredibly common need, but I've never
seen anything designed to support it.  Closest thing I've seen is
http://www.blackie.dk/emacs/narrow-stack.el, but it only handles part of
the problem.  Anyone got a hint for me?

Thanks,

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com