import win32com.client
from win32com.client import constants as C
propName = "TheProperty"
gridDataName = "TheGrid"
siProperty = Application.ActiveSceneRoot.AddProperty( "CustomProperty", False, propName )
gridData = siProperty.AddGridParameter( gridDataName ).Value ;
gridData.ColumnCount = 2
gridData.RowCount = 2
for row in range( 2 ):
        gridData.SetRowLabel( row, "Row %d"%row )
        for col in range( 2 ):
                # Only set column labels once (when processing the first row)
                if row == 0:
                        gridData.SetColumnLabel( col, "Col %d"%col )
                gridData.SetCell( col, row, "%d,%d"%( col, row ) )
# Insert a blank column between row 0 and 1
gridData.InsertRow( 1 )
Application.InspectObj( siProperty )