i would be tempted to just use a decent text file editor (like Ultraedit) to edit the lines by turning such lines as ...

1,3,01-dec-2002,john,smith

... into ...

insert into my_table values(1,3,to_date('01-dec-2002'),'john','smith');

i find it takes me less tha n a minute to do so, and the n the file can be pasted into SQL*Plus. Much faster for this data volume than writing/debugging sql*loader