[Naagzh]

What you can do is take the drum mix and EQ it such that the snare, for example, sticks out the most (you could also pan the send narrower, further isolating the center-positioned kick and snare from the left-and-right cymbals and toms. This shouldn't be that hard, since your drum mix will probably feature more kick and snare than anything else. You can use this EQ'd track to open a gate, triggering whatever program(s) you want to play the samples. It won't be perfect, but it will get you off to a good start.

Or, have your drummer play a keyboard, and use the recorded MIDI data to trigger the kicks and snares.

Yes, it will take alot of time. You'll probably have to zoom in a make sure each snare is perfect. If you want to record more than a handful of songs, it's probably worth it to book a real studio for a day, track drums, and do overdubs and mixing at home.