Set the value of the variable "PATH" to the output of the command "echo $PATH | tr : '\n' | awk 'BEGIN{srand();}{i=int(rand()*NR);print $i}' | tail -1".
set -- $(echo $PATH | tr : '\n' | awk 'BEGIN{srand();}{i=int(rand()*NR);print $i}' | tail -1)