Drumagog is designed to trigger drum samples off of an audio signal (from a close mic'd track). All you need is something that uses the midi information to trigger samples. What software are you using? There's a ton of stuff I've seen for VST hosts, I have some freeware one that I've never had much luck with, but I haven't really tried messing with it too much. The thing I usually play with is either lm-7 or lm-9, I can never remember which one. Just a vst drum instrument.... it works pretty well, but it's not designed for use with all sorts of samples... only way to use different samples is to go in and manually swap the wave files it uses. Something that's designed for just triggering samples from midi hits is what you want. You might have to play around a bit to set it up to be taking the right input and doing the right thing with it.
Hopefully someone has some good suggestions about what to use... any good freeware plugins anybody likes for this?