In your worksheet, you either have, or could add, a range parallel to
your data which has totals. Copy this range, select the chart, and
paste special, with the new series option. This adds another stack,
which shrinks everything on the chart.
Right click on this new series, select chart type from the pop up menu,
and select a Line chart type. This gives you a set of lines connecting
the tops of the stacks. Double click the line series: on the Patterns
tab, select None for Lines and Markers; on the Data Labels tab, select
the Values option; press Okay. Finally, double click on the labels,
click on the Alignment tab, and choose the Above option for Position.
- Jon