SQL*Loader - 'adding' data while loading

I would like to populate FEED below even though it is not in the input file.

here is my table :

SQL> desc sep2001_new
 Name

 REPORTING_PERIOD                       
 SOURCE_ID                              
 ORG_UNIT                               
 PRODUCT                                
 IFA_INDICATOR                          
 IFA_BALANCE_AMOUNT                     
 IFA_RATE                               
 IFA_RATE_SOURCE                        
 FUNDING_GROUP                          
 FEED                                   

here is my ctl file :

load data
infile 'c:\orant\bin\sep2001.txt'
into table sep2001_new
fields terminated by "," optionally enclosed by '"' (REPORTING_PERIOD,

SOURCE_ID,                     
ORG_UNIT,                     
PRODUCT,
IFA_INDICATOR,                    
IFA_BALANCE_AMOUNT,
IFA_RATE,
IFA_RATE_SOURCE,            
FUNDING_GROUP,
FEED          "decode(:org_unit,'11114','BOOK1','BOOK2','STUDLN',null)")

My input file does not contain a column for FEED.

I tried the decode above but get the following error :

Error on table SEP2001_NEW, column FEED. Column not found before end of logical record (use TRAILING NULLCOLS) Received on Thu Oct 25 2001 - 15:50:17 CDT