I want to read value in column APAPNO with column App no. in sheet Extra.
It found in sheet Extra —> write text Extra in that row in sheet Data. (in highlight yellow)
Could you try this instead and let me know if that works out for you?
(From row In dt_data.AsEnumerable()
Let status = If(lst_appNumbers.Contains(row("APAPNO").ToString.Trim),"Extra","")
Let ra = row.ItemArray.Take(2).Append(status).Concat(row.ItemArray.Skip(3)).ToArray()
Select dt_updatedData.Rows.Add(ra)).CopyToDataTable()
(From row In dt_data.AsEnumerable()
Let status = If(lst_appNumbers.Contains(row("APAPNO").ToString.Trim),"Extra","")
Let ra = row.ItemArray.Append(status).ToArray()
Select dt_updatedData.Rows.Add(ra)).CopyToDataTable()