Thanks for using Aspose APIs.
Please use Range.SetStyle() for your needs. Please see the following sample code.
It gets the style from cell A1 and applies it to range of your choice.
Please also check the output Excel file generated by the code as well as the screenshot showing the effect of the code on source Excel file.
source and output excel files.zip (11.9 KB)
sc.png (48.6 KB)
Workbook wb = new Workbook("sample.xlsx");
Worksheet ws = wb.Worksheets;
//Get the style from cell A1 and apply it to range of your choice
Cell cell = ws.Cells["A1"];
Style st = cell.GetStyle();
Range rng = ws.Cells.CreateRange("G2:H4");