What is wrong with this statement:

CREATE TABLE "EXT_PLUSALES"
EXTERNAL FILE 'C:\PLUSALES.ASC'
( STOREID VARCHAR(10) NOT NULL,
SALESDATE TIMESTAMP NOT NULL,
PLU VARCHAR(14) NOT NULL,
QUANTITYSOLD FLOAT,
COSTEXGST FLOAT,
COSTINCGST FLOAT,
SALESEXGST FLOAT,
SALESINCGST FLOAT,
PRIMARY KEY ( STOREID, SALESDATE, PLU ));

I get this message:

ISC ERROR CODE:335544831

ISC ERROR MESSAGE:
Access to external file "C:\PLUSALES.ASC" is denied by server
administrator

I am using Firebird 1.5.2 classic.

Regards,

Robert.