It is possible to use Text and Excel files (*.txt, *.csv, *.prn, *.asc, *.xls, *.xlsx) as sources of data when creating queries using Web Intelligence Rich Client, and you can also use Excel files as data sources in Web Intelligence.

Local-Data-Sources

In this session we show you how to query Local Data Sources and then use Merged Dimensions to combine the data for analysis.

32 – Using Local Data Sources in Web Intelligence Documents