Property	GroupIndex: Integer (R/W)
Description
This is an index of the column within a grouping. A grouping may contain more than one column.
Use this property to create a grouping at runtime (in code).
Code Snippet
   'enable grouping
idbgridPart.groupbybox = true
   columnPartGrpCode.GroupIndex = 0      'partgrpcode is the first group
   columnPartType.GroupIndex    = 1      'parttype is the second group
   
  'disable grouping
   idbgridPart.groupbybox = false
   columnPartGrpCode.GroupIndex = -1
   columnPartType.GroupIndex    = -1