Overlapping keys can be a problem. You might be able to just issue CREATE TABLE statement (adding the USING and IN DICTIONARY clauses) to create the table definition. You could add one index but not the second (overlapping key definition). It might not be the best performance (if your export query would optimize on that missing key), but it should work.

The only way to export data without creating table definitions would require using the Btrieve API and knowing the record structure.

You could also contract with someone to create the DDFs or Btrieve API program.