For your report, you can specify a filtering expression (of virtually any level of complexity), to exclude excessive or undesired data.
To filter a report's data, click its Smart Tag, and in the invoked actions list, click the ellipsis button for the Filter String entry. Then, in the invoked Filter String Editor, construct an expression.
In the Filter String Editor, you can either use the Visual expression builder, or specify the expression in Text.
Note that it is possible to embed parameters into the expression, and also request them each time a report is previewed.
To quit the dialog and save the changes, click OK.