On the ESX Server you will find the iso for the VMware Tools in the /usr/lib/vmware/isoimages/windows.iso. Use WinISO or WinRAR to extract the files into a folder.

Place the reference to the VMWare tools in the RunOnceEx.cmd to a batch file.

REG ADD %KEY%\017 /VE /D "VMWare Tools for ESX 2.5.2" /f
REG ADD %KEY%\018 /V 1 /D "%systemdrive%\Drivers\VMware.cmd" /f

The batch file to launch the VMWare tools.
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@echo off
%systemdrive%\Drivers\setup.exe /S /v"/qn ADDLOCAL=ALL REBOOT=ReallySuppress
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Voila!
The cake is ready, serve with ice cream and coffee!