We use the Sybase OLEDB provider to connect
OLEDB CONNECT32 TO [Provider=Sybase.ASEOLEDBProvider.2;Initial Catalog=tempdb;User ID=<userid>;Data Source=<servername>;Extended Properties=""] (XPassword is VXYIDbJOJTaIWQdMRJOYN);
With ODBC you are required to set up a datasource. With Sybase OLEDB you still need a .ids config file with the serverdetails (made with the Sybase ASE OLEDB Configuration Manager).
I found a variety of options at this site
This is the option that worked for me:
But it did involve choosing OLEDB rather than ODBC.