Hello Dimitry,

attaching a database can be done from any folder but I would recomment putting the files where all the databases are...

here is an article that explains how to attach/detach a database using system stored procedures

http://databasejournal.com/features/mssql/article.php/2224361

http://support.microsoft.com/default.aspx?scid=kb;en-us;Q224071

You can also find information on how to do it using Enterprise Manager in the Books Online,
search for "Attaching and Detaching a Database"

Hope that helps,

Alex