hi, I'm new to Vb.net and I need a little help. I have this Code to Export All Data from Datagridview to Excel and it works well, Problem 1 :

But what I want to do is To export only Specific columns, not all columns from Datagridview (Example I want to Export only Column 3 and 5) Not all Columns.

And Problem 2:
is It is possible to export in an existing template example I have an excel template with Name And ID to export in this existing template not in new.

Thank You.

Code:
   ' Creating a Excel object.
        Dim excel As Microsoft.Office.Interop.Excel._Application = New Microsoft.Office.Interop.Excel.Application()
        Dim workbook As Microsoft.Office.Interop.Excel._Workbook = excel.Workbooks.Add(Type.Missing)
        Dim worksheet As Microsoft.Office.Interop.Excel._Worksheet = Nothing

        Try
            worksheet = workbook.ActiveSheet

            'worksheet.Name = "ExportedFromDatGrid" '
            worksheet.Name = Me.Text ' 
            Dim cellRowIndex As Integer = 1
            Dim cellColumnIndex As Integer = 1

            'Loop through each row and read value from each column.
            For i As Integer = -1 To dgw.Rows.Count - 1
                For j As Integer = 0 To dgw.Columns.Count - 1
                    ' Excel index starts from 1,1. As first Row would have the Column headers, adding a condition check.
                    If cellRowIndex = 1 Then
                        worksheet.Cells(cellRowIndex, cellColumnIndex) = dgw.Columns(j).HeaderText
                    Else
                        worksheet.Cells(cellRowIndex, cellColumnIndex) = dgw.Rows(i).Cells(j).Value.ToString()
                    End If
                    cellColumnIndex += 1
                Next
                cellColumnIndex = 1
                cellRowIndex += 1
            Next

            'Getting the location and file name of the excel to save from user.
            Dim saveDialog As New SaveFileDialog()
            saveDialog.Filter = "Excel files (*.xlsx)|*.xlsx|All files (*.*)|*.*"
            saveDialog.FilterIndex = 2

            If saveDialog.ShowDialog() = System.Windows.Forms.DialogResult.OK Then
                workbook.SaveAs(saveDialog.FileName)
                MsgBox("Export Successful", vbInformation)
            End If
        Catch ex As System.Exception
            MessageBox.Show(ex.Message) 'e paraqet probleim ne mesazh
        Finally
            excel.Quit()
            workbook = Nothing
            excel = Nothing
        End Try