Try this:
Dim ListOfSortedID As New List(Of Integer)
Dim IDs As String = String.Join(",", ListOfSortedID)
Where4Crystal = String.Format("{DutyView.EmpAutoID} in [{0}]", IDs)
You need the square brackets aroung
IN
operator.
Note: as far as i remember there's limitation to 32 arguments in IN operator.