How would i capture the Mute, Lights Off and Dolby Key ive managed to get all key events with the Gma.UserActivityMonitor API but this does not capture the mute, lights off dolby, camera and media button.

Any Ideas?

could possibly be managed via usb via serial data messages like an old video game controller.

a good place to start would be looking through the device manager and see if you can find the device that manages them in the list of devices, possibly as a HID compatible input (which can be communicated with fairly easily) or other usb type device.