Congratulations, Faster... It works fine, just my minor modification :
;;Get all parameters for lwpolyline.
(defun gxl-getlwparamatpoint (LW PT / DATA DPA PA PARS EL V K NEWEL A)
...
(if (equal pt (vlax-curve-getendpoint lw) 1e-8) (setq pars (cons (vlax-curve-getendparam lw) pars)))
(reverse pars)
)
M.R.