If any of your ideas would be potentially useful internally too, you might be better off hiring people rather than finding a cofounder.
Otherwise, following his description literally, he wants a web-based way to share read-only copies of random spreadsheets.
I am constantly searching for datasets from Government websites, market data, etc. Wolfram alpha has the data but its not free. The federal government data is bloated and takes forever to parse. Why couldn't someone post an excel sheet of the data for everyone to use?