I am trying to programmatically generate a 9-panel chart similar to
those you see in stock prospectuses, with the horizontal displaying
"Investment Style" and the vertical displaying "Market Cap". Each of
the 9 panels within the grid represents a different combination of the
horizontal vs. vertical values.

I have a very kludgy solution using conditional formatting on a grid
of 9 individual cells to turn one of them on and leave the rest
neutral, but this solution is hard to maintain and expand for more
source data. I would like to take nine graphic files, one for each
possible highlighted square position, and use a formula to derive a
value that would be used to display a graphic with that filename. For
instance, for "Growth" and "Large", if the formula produced a result
of "GL", the file named "GL.jpg" (or GIF or PNG) would appear in a
certain cell (each of the nine graphic files would be identical in
dimensions). If the source data changes, the graphic would
automagically be changed, too. If two rows of data produce the same
combination of horizontal vs. vertical values, they would each display
the same graphic file.

How do I do this in Excel (2003, preferably)?

advTHANKSance!