SQL & PL/SQL

Is it possible to create a file in oracle directory path (in unix folder).

I am using a dynamic procedure to create the External Tables, when the given pattern file is present the procedure will create the External table, if the file is not present then it should create an empty file so that the corresponding External table would return zero(0) records. It should not fail.
It has to be through plsql not using unix script.

..............

UTL_FILE.FGETATTR(V_DIR_NAME, V_FILE_NAME, V_EXISTS, V_FILE_LENGTH, V_BLOCKSIZE);

IF v_exists=FALSE THEN
--------create an empty file
v_file_name:=empty_file;
end if;

--Create table script which will dynamically create the external table

v_sql := 'CREATE TABLE '||V_RX_NAME||' ( '||RTRIM(v_cols,', ')||' )' ||
' ORGANIZATION EXTERNAL '||
' ( TYPE ORACLE_LOADER '||
' DEFAULT DIRECTORY "'|| v_dir_name || '"'||
' ACCESS PARAMETERS '||
' ( RECORDS DELIMITED BY NEWLINE '||
' LOAD WHEN ( '||RTRIM(v_null_cols,'and ')||')'||
' BADFILE '''||rec_mkt_name.SUBJECT_AREA_NAME||'_'||rec_mkt_name.PARAM_NAME||'.BAD''' ||
' DISCARDFILE '''||rec_mkt_name.SUBJECT_AREA_NAME||'_'||rec_mkt_name.PARAM_NAME||'.DISCARD''' ||
' LOGFILE '''||rec_mkt_name.SUBJECT_AREA_NAME||'_'||rec_mkt_name.PARAM_NAME||'.LOG'''||
' FIELDS TERMINATED BY ''~'' OPTIONALLY ENCLOSED BY ''"'' '||
' MISSING FIELD VALUES ARE NULL ' ||
' ) LOCATION ('''||V_FILE_NAME||''') ) REJECT LIMIT UNLIMITED';
GV_CURR_STEP := v_sql;
dbms_output.put_line(V_FILE_NAME) ;

EXECUTE IMMEDIATE v_sql;
...........