[jboss-as7-dev] Configuration conundrum with Express

Warning, I may be repeating an existing query, so tell me politely where to go if that is the case ;-) I've been adding Express support to Forge, in the run up to doing demos at JavaOne. I've hit the point where I want to add an entry (an Infinispan cache) to the standalone.xml (or domain.xml), and I want to do it without having to write a parser. If the node is available via the mgmt interface this is easy - I can use the REST interface etc. However, my node isn't, and the recommended way to configure it is to edit .openshift/configuration/standalone.xml. Any thoughts on how I can make use of the management capabilities of AS to define this (in a machine controllable way without me reinventing the wheel) for OpenShift Express?