plpgsql Field of Record issue

Is there any other way to accomplish NEW.TG_ARGV[0] in plpgsql, or am
I stuck writing a C function which will allow:
_value := getRecordValue(NEW, TG_ARGV[0]).

create table test(col1 int4);

create or replace function test() returns opaque as '
declare
_value int4;
begin
RAISE NOTICE ''Args: %'', TG_NARGS;
RAISE NOTICE ''Column: %'', TG_ARGV[0];

-- PARSE ERROR
_value := NEW.TG_ARGV[0];

RAISE NOTICE ''Data: %'', _value;
end;
' language 'plpgsql';

create trigger name BEFORE INSERT ON test
FOR EACH ROW
EXECUTE PROCEDURE test('col1');
--
Rod Taylor

Your eyes are weary from staring at the CRT. You feel sleepy. Notice
how restful it is to watch the cursor blink. Close your eyes. The
opinions stated above are yours. You cannot imagine why you ever felt
otherwise.