ต้องการผสานเซล 1 คอลั่ม 1-7 ของ excrel ให้เป็นหัวเรื่องต้องแก้โค๊ดยังไง

 Private Sub GirdToExcel(ByRef dgvw As DataGridView)
        Dim excel As New Microsoft.Office.Interop.Excel.Application
        Dim Libro As Microsoft.Office.Interop.Excel.Workbook
        Dim Hoja As Microsoft.Office.Interop.Excel.Worksheet
        Dim col As Integer = dgv_2.ColumnCount
        Dim row As Integer = dgv_2.RowCount
        Libro = excel.Workbooks.Add
        Hoja = excel.Worksheets.Add()

        excel.Workbooks(1).Worksheets(1).cells(1, 1).columnWidth = 10
        excel.Workbooks(1).Worksheets(1).cells(1, 1).RowHeight = 20
       

        For i As Integer = 1 To col
            Hoja.Cells.Item(1, i) = dgv_2.Columns(i - 1).Name.ToString
            excel.Workbooks(1).Worksheets(1).cells(1, 1).value = ""
            excel.Workbooks(1).Worksheets(1).cells(1, 2).value = ""
            excel.Workbooks(1).Worksheets(1).cells(1, 3).value = ""
            excel.Workbooks(1).Worksheets(1).cells(1, 4).value = "รายงานงานเสร็จแล้ว"
            excel.Workbooks(1).Worksheets(1).cells(1, 5).value = ""
            excel.Workbooks(1).Worksheets(1).cells(1, 6).value = ""
            excel.Workbooks(1).Worksheets(1).cells(1, 7).value = ""

            excel.Workbooks(1).Worksheets(1).cells(2, 1).value = "ลำดับที่"
            excel.Workbooks(1).Worksheets(1).cells(2, 2).value = "รหัสงาน"
            excel.Workbooks(1).Worksheets(1).cells(2, 3).value = "คำนำหน้า"
            excel.Workbooks(1).Worksheets(1).cells(2, 4).value = "ชื่อ"
            excel.Workbooks(1).Worksheets(1).cells(2, 5).value = "จังหวัด"
            excel.Workbooks(1).Worksheets(1).cells(2, 6).value = "ผู้ประเมิน"
            excel.Workbooks(1).Worksheets(1).cells(2, 7).value = "ราคาประเมิน"

        Next
        For fila As Integer = 0 To row - 1
            For e As Integer = 0 To col - 1
                Hoja.Cells.Item(fila + 3, e + 1) = dgv_2.Rows(fila).Cells(e).Value

            Next
        Next
        Hoja.Rows.Item(1).font.bold = 2
        Hoja.Rows.Item(2).font.bold = 1
        Hoja.Rows.Item(1).horizontalAlignment = 3
        Hoja.Columns.AutoFit()
        excel.Application.Visible = True
        excel.Application.WindowState = Microsoft.Office.Interop.Excel.XlWindowState.xlMaximized
        Hoja = Nothing
        Libro = Nothing
        excel = Nothing

    End Sub