SQL & PL/SQL

I have a directory TEST_DIR which points to /test/files/


CREATE OR REPLACE PROCEDURE file_exist (v_country in varchar2) is

v_check_file_exist BOOLEAN;
v_dir VARCHAR2 (256) := 'TEST_DIR';

begin

UTL_FILE.fgetattr (V_DIR || V_COUNTRY,'file123' ||'.txt', v_check_file_exist, v_a,v_b);
IF NOT v_check_file_exist THEN
DBMS_OUTPUT.put_line (TO_CHAR(from_date,'YYYYMMDD')||'.rds');
END IF;
END LOOP;


I would like to change the directory path based on the country which is passed as input to the procedure

exec file_exist('IND'), so in this case I want the procedure to look for file 'file123.txt' under path /test/files/IND.

But this is not working..

But when I change the directory to

create or replace directory TESTDIR as '/test/files/IND' and then change my UTL_FILE.fgetattr (V_DIR,'file123' ||'.txt', v_check_file_exist, v_a,v_b)(removing || v_country, this time it works.

am trying this as I have many country folders under the path like
/test/files/IND
/test/files/USA
/test/files/AFR
and want to change the direcotry path dynamically according to input given.

Any suggestions