Search Facility in web site

I want to provide search facility in my web site so that i have used indexing service but i face problem with excel files

indexing service not search properly into excel files. i have one folder in that i have some files  of pdf doc and xls format

when user enter any key word i want to search  in the files that under that folder

how can i do that is it there any other solution or how to use indexing service with excel

plz help
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