Excel 2007 : Stacked Graphs

Please help a desperate man!

We produce some monthly satisfaction scores, i.e January 67%, February 71% etc Naturally this is just a simple bar chart with months and the scores. However I have now been asked to work out the % of positive, negative and neutral scores. They want the chart to be presented by having the normal barc chart with scores and then within each bar to have the %'s of positive, Negative and neutral.

I have tried everything and cannot achieve this including setting up secondry Axis etc

HELP as I only have a day to do this