datatable values can be changed

Question

i have one dataset with the name dtPOlinesdata i was copied that data to exportdatatable it is also datatable i delete some rows in exportdatatable that rows also delted in original table that is dtpolinesdat what can i will do not change the original one when the exportdatatable is changed the following is the code.... see this

exportDataTable = New DataTable()
         exportDataTable = dtPOlinesdata
        Dim i As Integer = exportDataTable.Rows.Count
        i -= 1
        While i > 0
            ' MessageBox.Show(exportDataTable.Rows(i)("select"))
            If Not exportDataTable.Rows(i)("select") Then
                exportDataTable.Rows.Remove(exportDataTable.Rows(i))
                i = exportDataTable.Rows.Count - 1
            Else
                i -= 1
            End If

        End While