Spline control points using autolisp

Hello,
I'm working on a project using AutoLISP where i came to a point on how can i
get spline control points after the first one.
say a 33 control point spline
the first spline is given by
(setq sp1_list (entget sp1))
(setq coord1 (cdr (assoc 10 sp1_list)))
how about rest of it
or just last one
regards,
Imran