Script to get the just bounded lease

Hi,

I want to use the script to get the data of the just new leased machine. I know that I can use a script to get them periodically, but, I prefer JUST NEW ONES only. To get them, I know I can use the Lease Script on the DHCP Server properties, but, wich are the variables that I can use on this windows of the lease that has trigger the script???
2018-06-10 15_36_18-Window.png
Regards and thanks in advance