I am trying to create a spline with 9 control points.

I am using a FLST and P51X method to create a group of keypoints and use as an input in BSPLIN

the issue i am facing is, when i am using BSPLIN, ,P51X,

I cannot directly put XV1,YV1... with P51X as an input

which is different from

BSPLIN, P1, P2, P3, P4, P5, P6, XV1, YV1, ZV1, XV6, YV6, ZV6

This is my code so far

start.txt

/prep7

csys,1

FLST,3,9,8

FITEM,3,0,0,0

FITEM,3,5,10,0

FITEM,3,10,15,0

FITEM,3,15,20,0

FITEM,3,20,0,0

FITEM,3,25,0,0

FITEM,3,30,0,0

FITEM,3,35,5,0

FITEM,3,40,0,0

K, ,P51X

FLST,3,9,3

FITEM,3,1

FITEM,3,2

FITEM,3,3

FITEM,3,4

FITEM,3,5

FITEM,3,6

FITEM,3,7

FITEM,3,8

FITEM,3,9

BSPLIN, ,P51X