controling lights from phone thru DVR?

My title pretty much says it. I want to know if it's possible to turn lights at home on/off using my android.

I currently have gDMSS and have a good connection with my DVR. I figured that since I can control my PTZ from my phone, there must be a way to control simple relays, thus allowing remote control of those circuits.

What say ye, oh guru's of CCTV?