How can I dynamically pass in an application classpath suffix to GlassFish v2 at startup?

More of the question:
"In GlassFish v1, you could create variables in domain.xml, which you could set as -Dvars in the startserv script, but asadmin start-domain doesn't use this script any more."

This question was discussed and answered in the GlassFish forum. See the forum thread How to pass properties to glassfishv2 startup/domain.xml?