//This was the hard way.  
public static Lookup.StatusDataTable GetStatuses(bool intranetMode)
        {
            //TODO: Handle Intranet vs Internet mode.  
            LookupTableAdapters.StatusTableAdapter sta = new LookupTableAdapters.StatusTableAdapter();
            Lookup.StatusDataTable sdt = sta.GetStatusData();
            DataRow[] rows = sdt.Select("Status <> 'Unapproved' and Status <> 'Closed'");            
            Lookup.StatusDataTable retVal = new Lookup.StatusDataTable(); 
            foreach(DataRow dr in rows)
            {
                retVal.Rows.Add(dr.ItemArray); 
            }
            return retVal; 
        }

//Here's the easy way: 
        public static Lookup.StatusDataTable GetStatuses(bool intranetMode)
        {
            LookupTableAdapters.StatusTableAdapter sta = new LookupTableAdapters.StatusTableAdapter();
            Lookup.StatusDataTable sdt = sta.GetStatusData();
            if (!intranetMode)
            {
                sdt.DefaultView.RowFilter = "Status <> 'Unapproved' and Status <> 'Closed'"; 
            }
            return sdt; 
        }

public static Lookup.StatusDataTable GetStatuses(bool intranetMode)
        {
            //TODO: Handle Intranet vs Internet mode.  
            LookupTableAdapters.StatusTableAdapter sta = new LookupTableAdapters.StatusTableAdapter();
            Lookup.StatusDataTable sdt = sta.GetStatusData();
            DataRow[] rows = sdt.Select("Status <> 'Unapproved' and Status <> 'Closed'");            
            Lookup.StatusDataTable retVal = new Lookup.StatusDataTable(); 
            foreach(DataRow dr in rows)
            {
                retVal.Rows.Add(dr.ItemArray); 
            }
            return retVal; 
        }

Pretty intuitive, might be an easier/simpler way.

Filter Expression for a DataTable

data, filter

C#