Specifying multiple properties files

Hi,

I'm organizing different JMeter (2.8) tests by environment and I want to
have the following organization with respect to properties loaded at
startup:

1. Load jmeter.properties file (contains only jmeter-specific properties)
2. Load common.properties file (contains common properties shared by many
tests)
3. Load test-specific properties file (contains properties specific to the
current script)

Ideally, I want to load all of the above files at startup and I've tried to
do this using the -G[propsfile] argument (specifying 3 separate
-G[propsfile] arguments: 1 for each properties file). However, this doesn't
seem to work and the JMeter doc is vague on this subject.

Does anyone know if what I'm trying to do above can be done? I know I can
arrange the properties into 2 files (jmeter.properties and a setting
pointing to a user.properties file) but I really want more flexibility than
that.

Thanks,

Tom