Formatting Borders for excel output

[Desperado]

Hi All,

I'm trying to remove the grey border when we save the report in excel. I can do this manually by selecting the report in excel and formatting the border and pattern. I want to apply the same dynamically. When a user clicks on open the report in excel 2002 format, it should be displayed with out the grey border line. is there any way that i can alter some .CSS files or something( i don't know exactly) and get my desired output ??

Thanks in Advance