what you would do in cubase is go to Devices and click VST Instruments, then load the DFHS plugin from there.
then on the in/out MIDI track in your project, you click on "out" and select "Drummer" from the list. that sets it up so that the MIDI output runs through the DFHS plugin, so whenever you hit a key on the piano roll, it will play a drum sound.
i don't think Cubase LE has any plugin delay compensation (Reaper does) so that kinda sucks. but anyway once you map out the whole song in MIDI, DFHS will bounce it to wav files for you.
you just have to arm Record in the "bounce" section of DFHS, then playback the song so that DFHS can record all the hits, then click bounce to write it to WAV.
you can also control the amount of bleed that each mic gets in DFHS, so you can get a more "roomy" sound, which really can help the drums to come alive. once you get all the wavs bounced, you can load each one to its own track in Cubase and disregard the MIDI section (i usually just mute the MIDI track instead of deleting it, in case i want to go back and change something). once all the wav's are loaded, then it's just like mixing recordings of a real drum set.