Hi,
Thanks for considering Aspose.
It's very simple using Aspose.Cells APIs, Please check the following example code for your need:
[C#]
Workbook workbook = new Workbook();
Worksheet worksheet = workbook.Worksheets[0];
Cells cells = worksheet.Cells;
cells["A1"].PutValue("a1-Antitrypsin");
cells["A1"].Characters(0, 1).Font.Name = "Symbol";
cells["A1"].Characters(0, 1).Font.IsBold = true;
cells["A1"].Characters(0, 1).Font.Color = Color.Red;
workbook.Save("d:\\test\\symbolcharacters.xls");
[VB]
Dim workbook As Workbook = New Workbook()
Dim worksheet As Worksheet = workbook.Worksheets(0)
Dim cells As Cells = worksheet.Cells
cells("A1").PutValue("a1-Antitrypsin")
cells("A1").Characters(0, 1).Font.Name = "Symbol"
cells("A1").Characters(0, 1).Font.IsBold = True
cells("A1").Characters(0, 1).Font.Color = Color.Red
workbook.Save("d:\test\symbolcharacters.xls")
Thank you.