There is no way to get this information from inside the report.  You would have to hardcode it or pass it in as a parameter (can't change it base on the param, but you can display the param.)

It's not necessarily so surprising - Crystal can connect to many different types of data.  For some databases you need a file name, for others you need just a server name, for others you need a server name and a database name.  Then for ODBC connections you need the connection name, which doesn't get you the actual database info - if you need the database info, Crystal would have to access that from the ODBC connection (if that can be done....).  So, it would be a very complex thing to code for this.