Specify different icon for app in window list & titlebar?

[Carl Miller <chaz energoncube net>]

Hi, this might seem a rather silly question, but I've got good reason for
it...

How can I change the icon (or specify one if the app comes with none) that
is displayed for a particular app in both:
  a) the left edge of the titlebar of the app's window under metacity and
     the "simple" window theme, and
  b) the window list applet in the bottom-edge gnome-panel
?

I've read through the Gnome user's guide, Admin's guide, searched the
mailing list archives, and poked all around in the GConf editor, and I'm
stumped.  Can anyone give me a hint?  Or if this isn't the proper list on
which to ask, could you redirect me to the proper list?


Ok, for those of you asking, "why on earth would you want to do that?",
here it is...  I'm setting up a new desktop box for my Mother.  She's
computer-clueless.  She probably hasn't even used a Windows PC for more
than a few hours in her life.  On the downside, she's got zero experience
to draw from.  On the upside, this means a Gnome desktop presents an equal
learning curve to a Windows desktop (and I insisted that if she wanted to
install Windows, she couldn't call me for help!).  I've managed to make it
clear that the "earth with modem in front of it" icon
(/usr/share/pixmaps/gnome-modem.png) means "that thingy which connects to
the Internet", in this case, GkDial.  I've added launchers for GkDial to
both the Applications/Internet menu and the top-edge gnome-panel,
associating gnome-modem.png with each.  So I get the "proper" icon in those
two places.  However, when I launch GkDial, I get that silly "corner folded
down blank sheet of paper" icon in the title bar and in the window list.
She's big on consistency, and will notice this little disconnect.  Thus,
I'd like to fix it before delivering the box.

Thanks!

                             -----Carl