var aspose = aspose || {}; aspose.cells = require("aspose.cells"); // Create an object of the Workbook class and load the source XLSX/XLS file. var wb = new aspose.cells.Workbook("sample.xlsx"); // Create another Workbook object. var excelWorkbook1 = new aspose.cells.Workbook(); // Copy the first sheet of the first book into second book by calling the copy(source) method. excelWorkbook1.getWorksheets().get(0).copy(wb.getWorksheets().get(0)); // Invoke the save method to save the file. excelWorkbook1.save( "CWBetweenWorkbooks_out.xls", aspose.cells.FileFormatType.EXCEL_97_TO_2003);