Oracle Tuning info discarded

When I add Oracle Tuning information in in query, Delphi does discard this
before executing the query.

Example: SELECT CODE, NAME /*+ INDEX ADDRESS_NAME */
               FROM ADDRESS
               WHERE ......etc.
The /*+ INDEX ADDRESS_NAME */ is specific information for the Oracle
database to instruct which index to use when executing the query.
Delphi does discard this information.
How can I prevent Delphi from discarding this information.

Thankx,
Aad