Hi,
You might want to check out New in SAP BI 4.1 SP02: Microsoft Excel as data source for Web Intelligence on http://scn.sap.com/docs/DOC-49324 for the centralized location for excel file detail.
Also, you can turn on the refresh on open option in Webi report so that the report will always fetch the excel file when it is viewed.
Hope this helps,
Jin-Chong
