Hi Nora
It is possible to make many styles in the same cell. I have created a sample please check it out.
IRange Range = sheet.Range["A1"];
Range.Text = "Bold and Italic";
IRichTextString rtf = Range.RichText;
IFont Font = workbook.CreateFont();
Font.Bold = true;
Font.Italic = true;
rtf.SetFont(0, Range.Text.Length-1,Font);
Sample:
BoldItalic.zipwith regards,
Chella.