Есть замечательная библиотека d2kwutil
Там прописана куча функций winapi
Из этого кусочку поймешь, как получали список файлов

SearchHandle number;
IsDirectory BOOLEAN;
begin
empty;
SearchHandle:=WIN_API_DIRECTORY_LIST.FirstFile(path||mask,FileName,IsDirectory, FALSE);
If FileName is not null Then
if not isDirectory or add_dirs then
if full_path then
FileName := path||FileName;
end if;
push(FileName);
end if;
loop
WIN_API_DIRECTORY_LIST.NextFile(SearchHandle, FileName, IsDirectory, FALSE);
If FileName is not null Then
if not isDirectory or add_dirs then
if full_path then
FileName := path||FileName;
end if;
push(FileName);
end if;
Else
exit;
End If;
end loop;
End If;
WIN_API_DIRECTORY_LIST.CloseSearch(SearchHandle);

и вот пример как через DIR

PROCEDURE POP_DIR ( s_PATH IN VARCHAR2, f_skip in varchar2) IS
filename VARCHAR2(256);
out_file Text_IO.File_Type;
in_file Text_IO.File_Type;
in_fileTST Text_IO.File_Type;
buf VARCHAR2(256);
buffer VARCHAR2(2000);
n number;
BEGIN

GO_BLOCK('CRV');
CLEAR_BLOCK(NO_VALIDATE);
filename:='c:\CMD_STATI.BAT';
out_file := Text_IO.Fopen(filename, 'w');
Text_IO.Put_Line(out_file,'DEL c:\RES_STATI.TXT');
Text_IO.Put_Line(out_file,'DIR '||s_PATH||' /a /b /O:N > C:\RES_STATI.TXT');
Text_IO.Put_Line(out_file,'DEL c:\CMD_STATI.BAT');
Text_IO.Fclose (out_file);
HOST('c:\CMD_STATI.BAT', NO_SCREEN);
----------------------------------------------------
filename:='C:\RES_STATI.TXT';
in_file := Text_IO.Fopen(filename, 'r');
LOOP
BEGIN
Text_IO.get_line(in_file, buf);
buf:=UPPER(buf);
IF buf IS NOT NULL AND INSTR(UPPER(buf),'.XML')!=0 AND UPPER(buf)!=UPPER(f_skip) THEN
SELECT COUNT(*) INTO n FROM load_protocol WHERE UPPER(vcfile_name)=UPPER(buf);

IF :CRV.name IS NOT NULL THEN
create_record;
END IF;
:CRV.NAME:=buf;
:CRV.INCLUDE:=1;
IF n>0 THEN
:CRV.PRIM:='Файл с таким именем ранее загружался';
:CRV.INCLUDE:=1;
END IF;
END IF;
EXCEPTION WHEN OTHERS THEN EXIT;
END;
END LOOP;
Text_IO.Fclose (in_file);
-- Подчищаем хвосты
filename:='c:\CMD_STATI.BAT';
out_file := Text_IO.Fopen(filename, 'w');
Text_IO.Put_Line(out_file,'DEL c:\RES_STATI.TXT');
Text_IO.Put_Line(out_file,'DEL c:\ATR_FILE.TXT');
Text_IO.Put_Line(out_file,'DEL c:\CMD_STATI.BAT');
Text_IO.Fclose (out_file);
HOST('c:\CMD_STATI.BAT', NO_SCREEN);

----------------------------------------------------------
EXCEPTION WHEN OTHERS THEN
null;
END;