Default schema in DSN

Is there some way to specify a schema in a DSN so that individual table
references in an app don't need to specify it, and so that the app doesn't
need to know what DB is on the back end? (The latter constraint means I
can't set the schema search path in the app.) I tried using "mydb.public"
as the DB name but the Data Source editor doesn't like that.)

I'm trying to migrate an old Paradox app to a client/server paradigm. I
installed psqlodbc_08_03_0100 on XP SP2 and have an 8.1.11 server on Linux.
The app uses the Borland Database Engine (BDE) to access the database.

I don't see a place in the Data Source configuration tool to set the schema
or a search path for a DSN.