ACPI Battery Device Driver

Windows ACPI Device Driver Shell / Wrapper. I would like to have someone create a Windows Device Driver to simulate a Battery - just as a laptop with windows can display battery remaining time from the internal battery. I'd like to have a way to inject the values I want it to see. I will then extend this shell / wrapper to inject values from an external DC to DC powersupply so that windows thinks its a battery and can perform shutdown, standby, etc using the built in ACPI stuff in Windows. This must be an installable device driver (inf or something similiar) that looks just like a standard Battery device to windows but allows me to pump in the values I want it to use.