Sending an ACPID Powerbutton event in ESXI

Question

I am trying to find out how to send the ACPID powerbutton even to to a linux virtual machine on ESXI 5 in order to execute the acpid powerbutton graceful shutdown script.

ACPID is already installed on the VM and the powerbutton event script is defined and working as this virtual M/C was cloned from a real virtual machine with a real powerbutton.

I thought that this would be simple, but due to the fact that google has returned no useful answers, I suspect that it can't be done.

Yes, I am aware of the vim-cmf power events, but the shutdown command requires that vmware tools be installed and this is a headless machine with no gui and accessed only via ssh.

Surely there is a way of sending the machine the acpid powerbutton event just as the motherboard / cmos would on a real machine without needing to install any software on the VM ??