Exchange Cluster On shutdown

We have an Exchange Server 2013 Cluster running on top of Windows 2012R2.

We want to be able to execute the following script on shutdown event: https://gallery.technet.microsoft.com/scriptcenter/Exchange-Server-2013-ff6c942f.

We tried to set it to run by GPO “Computer Configuration\Policies\Windows Settings\Scripts (Startup/Shutdown)” but without any success, the Cluster Events take precedence and the Exchange Database is put offline first.

We would like to know, how can we make the script execute before any Cluster Events.

Thanks in advance for your help