SparklineGroup.PlotBy (Excel)
Returns or sets how to plot the sparkline when the data on which it is based is in a square-shaped range. Possible return values are xlSparklineColumnsSquare, xlSparklineNonSquare, xlSparklineRowsSquare.
This property can only be set if the data on which the sparkline is based is in a square-shaped range, for example if the data is in the range A1:B2. The default value for sp data in a square-shaped range is to plot the data by rows (xlSparklineRowsSquare).
ActiveCell.SparklineGroups(1).PlotBy = xlSparklineColumnsSquare