Source Excel document:

New row was inserted and document saved as new document file:

using System;
using System.Collections.Generic;
using System.Text;
using Bytescout.Spreadsheet;

namespace Adding_rows_to_existing_XLS
{
class Program
{
static void Main(string[] args)
{
// Open Spreadsheet
Spreadsheet document = new Spreadsheet("AdvancedReport.xls");
// Get Worksheet
Worksheet worksheet = document.Workbook.Worksheets[0];
// Add new row
worksheet.Rows.Insert(6, 1);
// Set values
worksheet.Rows[6][0].Value = "New Name";
worksheet.Rows[6][1].Value = "New Full Name";
// Save document
document.SaveAs("AdvancedReport1.xls");
// Close Spreadsheet
document.Close();
}
}
}

Download example source code: bytescoutxls_adding_rows_into_existing_xls.zip (5 KB)