You may make use of this script. I automated loading on NT machine using this batch file.
Code:
@ECHO OFF
ECHO  Finding Data to be loaded...
CD C:\DATA\
FOR  %%V in (*.DAT) DO SQLLDR73.EXE username/password@db CONTROL=C:\CODE\PRE.CTL LOG=C:\LOG\PRE.LOG BAD=C:\LOG\PRE.BAD DATA=%%V ERRORS=1500
MOVE *.DAT C:\OUT\