Works great but no variables?

I love the plugin but I cannot get it to execute in the command defintion if I use %HOSTADDRESS% instead of the full IP.

Obviously, I need to be able to use vars to apply the service to all my VMware servers.

Any ideas? HEre are my command and service defs:

############## Command Definitions for VMWare Servers ##################################

define command {
command_name check_vmware_hardware
command_line /usr/lib/nagios/plugins/check_esxi_hardware.py -H %HOSTADDRESS% -U root -P ‘MYPASS’
}

############## Service Definitions for vmware Servers ###################################

define service{
use generic-service ; Name of service template to use
hostgroup_name vmware-servers
service_description System: ESXi HArdware Status
check_command check_vmware_hardware
}