Pointer array of pointer

Thanks for all. This is my first post.
I have a customized type such as

type dhd_particle
     real (kind=8) :: postn(3)=0.D0  ! position
     real (kind=8) :: veloc(3)=0.D0  ! velocity
     real (kind=8) :: vorti(3)=0.D0  ! vorticity
     real (kind=8) :: force(3)=0.D0  ! force
     real (kind=8) :: torqu(3)=0.D0  ! torque
end type

 and make 10 of them

type (dhd_particle) :: sphere(10)

 Now I have pointer array such as

real(kind=8),pointer :: x(10),y(10),z(10),r(30)

then link them like

  x => sphere(:)%postn(1)
  y => sphere(:)%postn(2)
  z => sphere(:)%postn(3)

up to which I did not have any problem.  What I want to have is a pointer of "r", of which components are

r(1) = x(1)
r(2) = y(1)
r(3) = z(1)
r(4) = x(2)
...
r(30) = z(10)

How could I make the pointer array r either using x, y, and z or directly form sphere array?
I first would like to know this is possible or not. If possible, how do I write a code?

Any help will be highly appreciated.

Albert