I think he means something more like using rhythmic events to control parameters of whatever other synth.
If so, this can be done by transforming the MIDI note events of whatever drum track into a controller message the other synth would be abe to read and use as, say, a modulation source.
And fwiw, with some synths you can even do this in realtime. Let's take the EXS for example. It offers a sidechain input as a modulation source, so it's quite easy to modulate whatever parameter you want by the sidechain input.
The sidechain can be fed either by an input, an audio track or a bus (unfortunately you need to use a bus in case you want to feed the sidechain with a virtual instrument signal - rather stupid, if you ask me...).
The ES2 offers a sidechain input, too.
Some third party synths allow for being used as a MIDI controlled FX, for example U-He Zebra 2 and NI FM8 (just to name two popular ones), that way they can make use of audio (or bus) inputs, too.