You can get some 1/4 inch to RCA cables and go right into the "line in" jacks on the BR 1200. This will give you a stereo mix, which is pretty much your only option unless you want to go MIDI. Here's a link to a thread on that: https://homerecording.com/bbs/showthread.php?t=310177
When I had V-Drums I just used the Left (main?) output into whatever I was recording with at the time. Not familiar with the br1200. How many INs does it have? If only 2, use L & R out of drum module. If multiple......
Bottom line is use as many INs & Outs as you've got. You can do it with just one, but your amount of tweakable tracks is reduced.