IDT ODBC connection to EXcel

We have set up a DSN on the BO server to connect to a spreadsheet which is stored on the server , the connection uses Excel version 12 . This works and a universe can be created of this spreadsheet . When I create a data foundation using this connection I can see all the excel workbooks in the folder not just the one named in the DSN . What I am trying to find out is if I can use this connection with any of these workbooks in this folder or if each workbook needs its own DSN .