I have the following as a control file

load data
infile '/mydir/MY_TRANS_20050915.DAT'
into table MY_TRANS
when (1) <> "TR"
fields terminated by '|'
trailing nullcols
(
FWT_ACCT_NO,
FWT_VALUE_DT DATE "YYYYMMDD",
FWT_POST_DT DATE "YYYYMMDD",
FWT_CONV_TRAN_AMT,
FWT_CONV_CASH_AMT ,
)

The fwt_conv_cash_amt is coming in the file as empty. How do I tell sqlloader if it is empty put a zero in there?