export datagrid to excel and format the columns

See more:

C#

ASP.NET

Hi friends,
I am using VS 2008 ,asp.net,c#.net.
I have numbers in decimal format in datagrid.
I want to export a decimal figure in datagrid to excel sheet with thousand separator and decimal separator.
Those numbers should be aligned right.
How to format the excel cell number format and alignment
for example 12,12,34,567.89.

thanks in advance