Best way to export specific columns from DataBound DataGridView to Excel

Hello,

I have the following code that will export the entire DataBound DataGridView to Excel. Looking for advice on the best way to export only certain columns. Basically I want to have a new form open when a user clicks on a button that will give the user to select what they want to export. I think will use checkbox controls to select the items to export. Should I create new dataset and then export or is there way to filter the coumns in the current DataGridView?

Here is the code that I am using to export all columns to Excel.

using xl = Microsoft.Office.Interop.Excel;
private void button1_Click(object sender, EventArgs e)
        {           
            xl._Application app = new Microsoft.Office.Interop.Excel.Application();
            xl._Workbook workbook = app.Workbooks.Add(Type.Missing);
            xl._Worksheet worksheet = null;
            app.Visible = true;
            worksheet = workbook.Sheets["Sheet1"];
            worksheet = workbook.ActiveSheet;
            worksheet.Name = "User Detais";
            for (int i = 1; i < dataGridViewResults.Columns.Count + 1; i++)
            {
                worksheet.Cells[1, i] = dataGridViewResults.Columns[i - 1].HeaderText;
            }
            for (int i = 0; i < dataGridViewResults.Rows.Count - 1; i++)
            {
                for (int j = 0; j < dataGridViewResults.Columns.Count; j++)
                {               
                    worksheet.Cells[i + 2, j + 1] = dataGridViewResults.Rows[i].Cells[j].Value.ToString();
                }
            }
            worksheet.Columns.AutoFit();
            worksheet.Cells.HorizontalAlignment = xl.XlHAlign.xlHAlignLeft;
            xl.Range rng = (xl.Range)worksheet.Rows[1];
            rng.Font.Bold = true;
}