SSIS Lookup - Set values programmatically

Hi All,
For the SQL 2008 SSIS Lookup Transformation, how do I get the 'Modify the SQL statement' checkbox to be selected programmatically? I can change it through the front end, but I can't find the property to change it programmatically.

As I set the properties:

.SetComponentProperty("SqlCommand", "SELECT [Lookup_Code], [Product_I] FROM [vSource]")

.SetComponentProperty("SqlCommandParam", "SELECT * FROM (SELECT [Lookup_Code], [Product_I] FROM [vSource]) [refTable] WHERE [refTable].[SUB_SYNM_C] = ? OR (SUBSTRING([refTable].[Lookup_Code], 1, 3) >= ? AND SUBSTRING([refTable].[Lookup_Code], 1, 3) <= ? AND SUBSTRING([refTable].[Lookup_Code], 4, 3) = 'XXX')")

.SetComponentProperty("ParameterMap", string.Format("#20;#20;#20;"))

As I need to use <= and >= comparisons.

But the checkbox is never ticked, can anyone please tell me what I need to do to tick the check box?

Thanks,