Multiple objects in copy SOP houdini

From houdini 12.5 help about copySop:


create a switch node and a copy sop

in copy sop turn on Stamp inputs
and create a Variable1 = switch  -----> value1 = fit01(rand($PT),0,(opninputs("../switch1")))


in switch node insert expression connecting the stamp variable :
stamp("./copy1","switch",0)