Selectively formatting colors in an Excel generated by using Datagrid in Flex

I have some data in my DataGrid which i am using to create Excel. But i need to selectively format certain cells like background colors and font. Is it possible in Flex.I have tried googling it but i was unable to find something to format the Excel cells. I am using com.as3xls.xls.Cell, com.as3xls.xls.ExcelFile and com.as3xls.xls.Sheet. I am not sure if this is even possible.

Thanks in advance,
Aman