alternate key on numeric field

How to convert or use a numeric field to put it into an alternate key for
accessing an indexed file ?

For example, I got :

ENVIRONMENT DIVISION.
..
INPUT-OUTPUT SECTION;
FILE-CONTROL.
SELECT FLIV ASSIGN TO DISK;
ORGANIZATION INDEXED;
ACCESS MODE DYNAMIC;
RECORD KEY IS COD-LIV;
ALTERNATE RECORD TTL-LIV;
ALTERNATE RECORD AUT-LIV DUPLICATES;
(* 1) // here I would use NTH-LIV, QT-LIV and QTR-LIV as
alternates key !!!
FILE STATUS IS FS-LIV;

DATA DIVISION.
FILE SECTION.
FD FLIV LABEL RECORD STANDARD;
VALUE OF FILE-ID IS "LIVRES.DAT".

01 ENR-LIV;
02 COD-LIV PIC 5(X).
02 TTL-LIV PIC 5(X).
02 AUT-LIV PIC 5(X).
02 NTH-LIV PIC 99.    <--- ??
02 QT-LIV PIC 99.       <--- ??
02 QTR-LIV PIC 99.     <--- ??

"gianluigi beuzard" <gbeuzard@skynet.be> wrote in message
news:441687d9$0$1176$ba620e4c@news.skynet.be...
> How to convert or use a numeric field to put it into an alternate key for
> accessing an indexed file ?
>
> For example, I got :
>
> ENVIRONMENT DIVISION.
>  ...
>  INPUT-OUTPUT SECTION;
>   FILE-CONTROL.
>    SELECT FLIV ASSIGN TO DISK;
>           ORGANIZATION INDEXED;
>           ACCESS MODE DYNAMIC;
>           RECORD KEY IS COD-LIV;
>           ALTERNATE RECORD TTL-LIV;
>           ALTERNATE RECORD AUT-LIV DUPLICATES;
>           (* 1) // here I would use NTH-LIV, QT-LIV and QTR-LIV as
> alternates key !!!
>           FILE STATUS IS FS-LIV;
>
> DATA DIVISION.
>  FILE SECTION.
>   FD FLIV LABEL RECORD STANDARD;
>         VALUE OF FILE-ID IS "LIVRES.DAT".
>
>   01 ENR-LIV;
>        02 COD-LIV PIC 5(X).
>        02 TTL-LIV PIC 5(X).
>        02 AUT-LIV PIC 5(X).
>        02 NTH-LIV PIC 99.    <--- ??
>        02 QT-LIV PIC 99.       <--- ??
>        02 QTR-LIV PIC 99.     <--- ??

Use something like
02 alt-key.
03 nth-liv pic 99.
03 qt-liv pic 99.
03 qtr-liv pic 99.
with
alternate record alt-key

Or, if the compiler recognizes split-keys
(Micro Focus, for example)
alternate record alt-key = nth-liv qt-liv qtr-liv