Как преобразовать datatable в XML

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Private Sub DatatableXml(ByVal dtTemp As DataTable)

    Dim _excel As New Microsoft.Office.Interop.Excel.Application
    Dim wBook As Microsoft.Office.Interop.Excel.Workbook
    Dim wSheet As Microsoft.Office.Interop.Excel.Worksheet

    wBook = _excel.Workbooks.Add()
    wSheet = wBook.ActiveSheet()

    Dim dt As System.Data.DataTable = dtTemp
    Dim dc As System.Data.DataColumn
    Dim dr As System.Data.DataRow
    Dim colIndex As Integer = 0
    Dim rowIndex As Integer = 0

    For Each dc In dt.Columns
        colIndex = colIndex + 1
        _excel.Cells(1, colIndex) = dc.ColumnName
    Next

    For Each dr In dt.Rows
        rowIndex = rowIndex + 1
        colIndex = 0
        For Each dc In dt.Columns
            colIndex = colIndex + 1
            _excel.Cells(rowIndex + 1, colIndex) = dr(dc.ColumnName)
        Next
    Next

    wSheet.Columns.AutoFit()

    Dim strFileName As String = "DataTable.xlsx"
    If System.IO.File.Exists(strFileName) Then
        System.IO.File.Delete(strFileName)
    End If
    wBook.SaveAs("DataTable.xlsx")
    wBook.Close()
    _excel.Quit()
End Sub

Что я уже пробовал:

следующая команда сохранит таблицу дат в excel
теперь как преобразовать datatable в xml

на первом ряду как элемент теги

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