This article describes how to create a custom function in Microsoft Excel using the ICustomFunction feature in the Aspose.Cells library. By loading an existing Excel file or creating a new Excel file, we can use the methods provided by Aspose.Cells to define and register custom functions and get the results. Finally, we save the modified Excel file to disk....function and use it in the spreadsheet to get the results. We will...newly defined function in a spreadsheet Java //Open the workbook...