SQL Openquery && Oracle

In SQL Server 2000 I have set up an Oracle linked server. When I run
the following query it runs fine:-

SELECT
*
FROM
OPENQUERY(LINKEDSERVERNAME,'SELECT * FROM ORACLETABLENAME')

However the following query does not work:-

SELECT
*
FROM
OPENQUERY(LINKEDSERVERNAME,'SELECT FIELDNAME FROM ORACLETABLENAME')

This error is returned:-

Server: Msg 7321, Level 16, State 2, Line 1
An error occurred while preparing a query for execution against OLE DB
provider 'MSDAORA'.
[OLE/DB provider returned message: ORA-00904: "FIELDNAME": invalid
identifier
]
OLE DB error trace [OLE/DB Provider 'MSDAORA' ICommandPrepare::Prepare
returned 0x80040e14].

Basically select * works ok, but if I specify the field(s) I need then
it errors. I have tried entering the field names in upper and lower
case but it makes no difference.

My real problem is that some dates in the Oracle database are pre 1753
which SQL server does not recognise so I need to convert (decode) them.

Any help would be appreciated.

Thanks
Chris