Sub AddRangeGroup( _
   ByVal startIndex As Integer, _
   ByVal count As Integer, _
   ByVal isRowGroup As Boolean _
) 

Dim instance As IRangeGroupSupport
Dim startIndex As Integer
Dim count As Integer
Dim isRowGroup As Boolean
 
instance.AddRangeGroup(startIndex, count, isRowGroup)

void AddRangeGroup( 
   int startIndex,
   int count,
   bool isRowGroup
)

fpSpread1.ActiveSheet.AddRangeGroup(0, 20, true);
fpSpread1.ActiveSheet.AddRangeGroup(0, 10, true);
fpSpread1.ActiveSheet.RangeGroupBackGroundColor = Color.Yellow;
fpSpread1.ActiveSheet.RangeGroupButtonStyle = FarPoint.Win.Spread.RangeGroupButtonStyle.Enhanced;

FarPoint.Win.Spread.IRangeGroupSupport rangeGroupSupport = (FarPoint.Win.Spread.IRangeGroupSupport)fpSpread1.ActiveSheet;
if (rangeGroupSupport == null)
{
return;
}
rangeGroupSupport.AddRangeGroup(0, 4, true);

FpSpread1.ActiveSheet.AddRangeGroup(0, 20, True)
FpSpread1.ActiveSheet.AddRangeGroup(0, 10, True)
FpSpread1.ActiveSheet.RangeGroupBackGroundColor = Color.Yellow
FpSpread1.ActiveSheet.RangeGroupButtonStyle = FarPoint.Win.Spread.RangeGroupButtonStyle.Enhanced

Dim rangeGroupSupport As FarPoint.Win.Spread.IRangeGroupSupport = CType(FpSpread1.ActiveSheet, FarPoint.Win.Spread.IRangeGroupSupport)
If rangeGroupSupport Is Nothing Then
   Return
End If
rangeGroupSupport.AddRangeGroup(0, 4, True)