dynamic field names in a function.

I want to be able to reference NEW.field_0 though NEW.field_x where x is 
coming from NEW.qty in a FOR loop of pl/pgsql function. Is this possible?

In other words:

FOR j IN 0..NEW.str LOOP
				
	ans := ''q'' || i || ''a'' || j;
	cor := ''q'' || i || ''c'' || j;
	eval := 'q'' || i || ''e'' || j;
				
	IF NEW.ans = NEW.cor
	THEN NEW.eval := 1;
	END IF;

END LOOP;