how to load field data that exceed 4000 characters by sqlldr .ctl with out changing table column datatype from nvarchar2(2000) to nclob in table

Question

i am trying to load a data through sqlldr to staging table which have more than 4000 characters. i don't want to change datatype from my existing nvarchar(2000) in staging table. how to to load data by removing some received data in that column in .ctl file to load into staging table?

my control file

load data
CHARACTERSET UTF8
APPEND INTO TABLE STAGING
FIELDS TERMINATED BY '\t'
TRAILING NULLCOLS
(uid,
linked char(4000))

and column datatypes in the table:

uid    not null number(12)
linked          NVARCHAR(2000)

Record 1: Rejected - Error on table STAGING, column LINKED. Field in data file exceeds maximum length

Data file: (second column facing problem starting with 242357)
 22        242357, 242359, 242375, 242376, 242395, 242421, 242422, 242423, 242424, 242425, 242426, 242427, 242428, 242429, 242431, 242432, 242433, 242434, 242435, 242436, 242437, 242438, 242439, 242441, 242442, 242443, 242445, 242446, 242447, 242448, 242449, 242451, 242452, 242453, 242454, 242455, 242456, 242457, 242458, 242462, 242463, 242464, 242465, 242466, 242467, 242468, 24247, 242524, 242525, 242533, 242535, 242544, 242551, 242552, 242553, 242554, 242556, 242557, 242558, 242559, 242565, 242577, 242636, 242646, 242727 ...... so on