How to do a random linkage of child VMDK

Hi,

Here is my requirement, Say i have chain of vmdk like follows,

parent.vmdk

child-1.vmdk

child-2.vmdk

child-3.vmdk

So now if i wanted to make a new linkage as child-1a.vmdk. So the chain should look as below,

parent.vmdk

child-1.vmdk

child-1a.vmdk

child-2.vmdk

child-3.vmdk

Is it possible to do?  VDDK documation says random linkage of child is possible. So how do i acheive this ? Any help on this

/Thanks