Create a new XRLabel, which is the only report control that supports custom summary calculations.
The value range encompassed by the summary function within a report implies an appropriate band to display the result. For example, the Group Header or Group Footer bands are most appropriate to display the result of a summary that is calculated within a group.
The label must be bound to any field that belongs to a data table involved in the script's calculations.
Specify the value range within a report that is encompassed by the summary function and set the XRSummary.Running property of the object returned by the XRLabel.Summary property.