Converted Crystal Report to SSRS where SQL clause is not working

Question

Could somebody help with with this SQL query? I have a where clause that is not working because it is from Crystal Reports and I'm not sure what it would be in SQL:

This is a daily report which gets row data from last Sunday to the current day of the week.

WHERE INSpecialDateRange (shiphead.ShipDate, 'WeekToDateFromSunday')

Full query is:

SELECT shiphead.PackNum,
       shiphead.ShipDate,
       shipdtl.PackLine,
       shipdtl.OurJobShipQty,
       shipdtl.OurInventoryShipQty,
       shiphead.Invoiced,
       orderdtl.UnitPrice,
       part.SearchWord 
FROM   (Epicor905.dbo.Part part
        RIGHT OUTER JOIN Epicor905.dbo.OrderDtl orderdtl ON (part.PartNum=orderdtl.PartNum)
                                                        AND (part.Company=orderdtl.Company))
        INNER JOIN (Epicor905.dbo.ShipDtl shipdtl
                    INNER JOIN Epicor905.dbo.ShipHead shiphead ON (shipdtl.PackNum=shiphead.PackNum)
                                                              AND (shipdtl.Company=shiphead.Company))
                    ON ((orderdtl.Company=shipdtl.Company)
                   AND (orderdtl.OrderLine=shipdtl.OrderLine))
                   AND (orderdtl.OrderNum=shipdtl.OrderNum)  
WHERE INSpecialDateRange (shiphead.ShipDate, 'WeekToDateFromSunday')
ORDER BY shiphead.PackNum