Yeah but I think I see what you mean.

Here is a new picture. This is what you mean by y-z plane?

Anyways I figure I have to use something like this:

Code:

for i=1 to nrpoint
;or what ever :)
x#=x_ponit(i)
y#=y_ponit(i)
z#=z_ponit(i)
; rotate x-axis
x1#=x#
y1#=(cos(ang)*y#)+(sin(ang)*z#)
z1#=(sin(ang)*z#)-(cos(ang)*y#)
;roate y-axis
x2#=(cos(ang)*x1#)+(sin(ang)*z1#)
y2#=y1#
z2#=(sin(ang)*z1#)-(cos(ang)*x1#)
;rotate z-axis
x1#=(cos(ang)*x2#)+(sin(ang)*y2#)
y1#=(cos(ang)*y2#)+(sin(ang)*x2#)
z1#=z2#
x_ponit(i)=x1#
y_ponit(i)=y1#
z_ponit(i)=z1#
next