pgloader CSV to table column formatting

What is the required syntax to convert data fields and insert default column values when using pgloader to load a table from a csv file?

We are migrating some of our code from Oracle to Postgres and I am having difficulty finding documentation and examples for some the tasks I am trying to accomplish.

Currently, I am trying to import a csv files into a Postgres tables using pgloader and a config files. I have been able to import flat csv files into temporary tables containing all character data type columns then using SQL statements with data type conversions to load into production tables. I have had adequate success loading text fields into table columns with specific data types (other than character). Examples are text to date and the various numeric fields. I am also trying to locate documentation or examples to enter default values into columns for fields NOT in the incoming csv file.

NOTE: The fields NOT in the csv file are filled in by other fields or with sql updates. Example the sample_date is parsed into sample_date_year, sample_date_month, sample_date_day and sample_date_week. Only the year portion of a date is required for the sample_date field.

Below is a draft of what I am working on with examples of my test table, control file input file and system command.

TestTable:
(
submission_date date NOT NULL,
sample_date_year smallint NOT NULL,
sample_date_month smallint,
sample_date_day smallint,
sample_date_week smallint,
sample_key integer NOT NULL,
species character varying(2) NOT NULL,
sex character(1),
length smallint,
weight real,
record_origin character(1) NOT NULL
) ;

Control File:
LOAD CSV
FROM -
(submission_date
, sample_date
, species
, sex
, length
, weight)
INTO postgresql://dbname:xxxx543(at)localhost:NNNNNN/username?TestTable
( submission_date
, sample_date
, sample_date_year
, sample_date_month
, sample_date_day
, sample_date_week
, sample_key
, species
, sex
, length
, weight
, record_origin)
WITH
skip header = 1,
fields optionally enclosed by '"',
fields escaped by double-quote,
fields terminated by ','

SET client_encoding to 'latin1',
work_mem to '128MB',
standard_conforming_strings to 'on'
;

Input File
"submission_date", "sample_date", "species", "sex", "length", "weight"
"20150721","20150101","01","F","99.99","9999"
"20150721","201501","02","M","9.99","999"
"20150721","2015","03",,".01","99"
"20150721","2015","03","F",,"99"
"20150721","2015","03","M",".01",

System Command:
system("pgloader --type csv --verbose --logfile $logfilepath/rc_load_err.log $bindirpath/data_load.pgl < $InfilePath/$Infilename");

In Oracle we used the following conversions however we are trying to migrate the routine to Postgres:
submission_date DATE "YYYYMMDD",
recovery_date_month CONSTANT 0,
recovery_date_day CONSTANT 0,
recovery_date_week CONSTANT 0,
recovery_location_key CONSTANT 0.
record_origin CONSTANT 'N')

Thank you very much for you advice and assistance.

Dan Webb
Pacific States Marine Fisheries Commission
Analyst/Programmer - Regional Mark Processing Center