Example:

//Instantiating a Workbook object
Workbook workbook = new Workbook();

//Adding a new worksheet to the Excel object
workbook.getWorksheets().add();

//Obtaining the reference of the newly added worksheet by passing its sheet index
Worksheet worksheet = workbook.getWorksheets().get(0);

//Accessing the "A1" cell from the worksheet
Cell cell = worksheet.getCells().get("A1");

//Adding some value to the "A1" cell
cell.putValue("Visit Aspose!");

//getting charactor
FontSetting charactor = cell.characters(6, 7);

//Setting the font of selected characters to bold
charactor.getFont().setBold(true);

//Setting the font color of selected characters to blue
charactor.getFont().setColor(Color.getBlue());

//Saving the Excel file
workbook.save("D:\\book1.xls");