static void Main(string[] args) { var workbook = GetWorkbook(ExcelPath); var inputSheet = workbook.GetSheet("Input"); if (inputSheet == null) { Console.WriteLine("Could not find input."); return; } // door infos var inputDoorCells = inputSheet.GetRow(11).GetCells(6); /* * Type of door / Calculation / Cycles / Cable Drum / Spring DInside / Number of springs * Type of door: Data!Z15 * Calculation: Data!V8 * Cycles: Data!N12 * Cable Drum: Data!AH22 * Sprint DInside: Data!N22 * Number of springs: Calculation!B41 */ var dataSheet = workbook.GetSheet("Data"); var data = dataSheet.GetCellsFromReference(new[] { "Z15", "V8", "N12", "AH22", "N22" }).ToList(); var calculationSheet = workbook.GetSheet("Calculation"); var springNumber = calculationSheet.GetCellFromReference("B41"); var results = workbook.GetSheet("Input").GetRows(new[] { 17, 18 }).Select(x => x.GetCells(9)); data.First().SetCellValue((int)Options.TypeOfDoorOperation.MechanicalIndustrial1And1_4Inches); // workbook.EvaluateAll(); // Compare results to excel. var tempPath = $"{Directory}AlcomexTor-Modified_{Guid.NewGuid()}.xls"; var fStream = new FileStream(tempPath, FileMode.Create, FileAccess.Write); workbook.Write(fStream); fStream.Dispose(); var modified = new FileStream(tempPath, FileMode.Open, FileAccess.ReadWrite); var modifiedWorkbook = new HSSFWorkbook(modified); modifiedWorkbook.EvaluateAll(); var test = modifiedWorkbook.GetSheet("Input").GetRows(new[] { 17, 18 }).Select(x => x.GetCells(9)); Console.WriteLine(); File.Delete(tempPath); }