Hi Rich,

You could set the plot area of a chart to a picture with your own map, then
use a scatter chart with 3 series to plot each branch with a coloured
marker.

There are a couple of samples here
http://www.edferrero.com/ExcelCharts...2/Default.aspx
to get you going. Probably a bit more elaborate than you need, but have a
look at "Vary colour and Weight" on page 2 and
"Map Chart Europe"

Ed Ferrero
www.edferrero.com