data manipulation before graphing.

[dawp]

I need to graph data from a query. However I cannot get the query to do what I want. I need to add the result of a simple sum in one record to another field in the next record. While this is possible inside a table I cannot find how to do it in a query. It is also possible to do it in a report, but I cannot graph the resulting data series from a report. Can any one help me please.