Well, usually you can combine charts by right-clicking the appropriate series
and choosing Chart Type and changing the chart type of the series. But I
can't combine a bar chart with a scatter chart, so that's not going to really
work.
You could change the data marker for the one data point to be a square, but
I don't know that you could get the rectangle.
So what I'd do is create a square and a rectangle on my slide (using
autoshapes). I'd copy the square, double-click the chart to activate it,
select the appropriate data point, and hit Ctrl+C to paste in the square. I'd
repeat for the rectangle. This link has specifics:
Charts with Picture Markers
http://www.pptfaq.com/FAQ00574.htm
Or maybe I'd use a combination -- change the data point for the square and
just paste the rectangle autoshape. (You might have to use two rectangles and
group them to get the positioning right -- one would be background colored,
the other would be the color you want the data point to be.)
Actually, I'm sure there's an easier (or at least a more elegant) way to do
what you're asking, but my brain isn't coming up with it right now.
