For info, it is highly unlikely that your security camera will provide the correct code(s) to start/ stop the R2. Some of us have constructed our own infrared controllers to do the job - Olsen has been "threatening" to offer a suitable device for several months but it has yet to be advertised on this forum.
However the R2 firmware has been updated to enable the device to start/stop recording if the video signal is present/not present. Your camera will need to be able to output some sort of signal to drive an analogue switch, relay or similar. Another option is to detect the infra red signal from the camera and use this to toggle the video feed.
More details about the R2 IR system can be found here:
www.microft.co.uk Click the link "Neuros"