Hey Matt,
I was wondering if the SDK support the abbility to make a driver that will enable you to run a macro that sends both an RF command (to the processor) but also send local IR commands (source device) simultaneously.
I don't believe you need the SDK or even a driver to achieve this.
Simply make the button standalone (right click, properties -> output) and then create a macro. Inside the macro you can output a local IR code directly from the remote and also trigger a system macro on an XP processor.