I am generating charts with excel and would like it, when printed to
be at a specific scale.

For instance, I have a xy chart which has a circle plotted on a grid
that I would like to print as 10 squares per inch (or possible 2
squares per centemeter) grid on the paper, and the circle to be
precisely 3 inch diameter.

Any assistance or direction would be appreciated.

Thanks in advance,
TomC