I want to merge and put borders around text. This text is comes after datagridview data.

This is my code:
Code:
Imports Microsoft.Office.Interop

Public Class Form1

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'TODO: This line of code loads data into the 'ATSDatabaseDataSet.ATS' table. You can move, or remove it, as needed.
        Me.ATSTableAdapter.Fill(Me.ATSDatabaseDataSet.ATS)

    End Sub

    Private Sub DataGridView1_CellFormatting(sender As Object, e As System.Windows.Forms.DataGridViewCellFormattingEventArgs) Handles DataGridView1.CellFormatting
        DataGridView1.Rows(e.RowIndex).HeaderCell.Value = CStr(e.RowIndex + 1)
    End Sub

    Private Sub releaseObject(ByVal obj As Object)
        Try
            System.Runtime.InteropServices.Marshal.ReleaseComObject(obj)
            obj = Nothing
        Catch ex As Exception
            obj = Nothing
        Finally
            GC.Collect()
        End Try
    End Sub

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim xlApp As Excel.Application
        Dim xlWorkBook As Excel.Workbook
        Dim xlWorkSheet As Excel.Worksheet
        Dim misValue As Object = System.Reflection.Missing.Value
        Dim i As Integer
        Dim j As Integer

        xlApp = New Excel.Application
        xlWorkBook = xlApp.Workbooks.Add(misValue)
        xlWorkSheet = xlWorkBook.Sheets("sheet1")

        For i = 0 To DataGridView1.RowCount - 2
            For j = 0 To DataGridView1.ColumnCount - 1
                xlWorkSheet.Cells(i + 18, j + 2) = DataGridView1(j, i).Value.ToString()
            Next
        Next
        Dim lastRowForGrid As Integer = (DataGridView1.ColumnCount - 1) + 18
        xlWorkSheet.Cells(lastRowForGrid + 18, 1) = "This is the paragraph after datagridview data."


        xlWorkSheet.SaveAs("C:\Users\Programmer RBP\Desktop\vbexcel.xlsx")
        xlWorkBook.Close()
        xlApp.Quit()

        releaseObject(xlApp)
        releaseObject(xlWorkBook)
        releaseObject(xlWorkSheet)

        MsgBox("You can find the file C:\Users\Programmer RBP\Desktop\vbexcel.xlsx")
    End Sub
End Class