I'm not sure what language you are using but in the likes of ASP and ASPX you can connect to pretty much any datasource using ADO or ADO.net and then query your data using SQL.
So to do what you want would require the apropriate text database driver and an SQL string like so :
SELECT * FROM Countries.csv WHERE Country LIKE 'Somerset'
If you are using ASP this article explains it.
http://msdn.microsoft.com/library/de...ng03092004.asp