dendrogram

Hi,
I can determine a specific similarity threshold with the option
colorthreshold. For example when I choose as a threshold 0.6 then the
leafnodes with a higher similarity than 0.6 are marked in color. Is
there a possibility to get to know the leafnodes which are marked? As
a result I would like to have an array: r = [ 23 43 54 55] which
means that the elements 23,43,54,55 form a cluster with a similarity
0.6.
Thank you very much for your help!!
Martin
.