Rofl, they shouldn't even have that preset beat function, it kinda disguises the real use of EX drummer, as a VST.
On Cubase, make a new MIDI track, press F11 and load EZ drummer. Then change where it says OUT to ezdrummer. Change where it says NO MAP to GM MAP
On the MIDI track, select a section in blue and double click it to make a MIDI part, then double click that MIDI part and select the drumstick tool at the top. Then jsut program in what you want