Its not super-quick with clusters, but here's what I'd do: Use a For loop to index out each cluster from the array. Then unbundle the cluster. Then add the 3 unbundled elements and your new 4th element using the bundle function - this will make your new array. See the LV 6 attached. Good luck with it, Doug
When you create a cluster, it's always a good idea to make it a typedef. This allows you to only need to make changes in one place, and the changes are propogated through all instances. If this cluster were a typedef, all you would need to do is add the element in the cluster in the typedef.