Is it possible to export a song, a pattern or a track to the MIDI File Format using Renoise?
There are a few ways to do this.
One way is trying to use Thalamus ( http://www.jaltoh.6x.to/ ) or another MIDI interpretor like MIDIYoke and then importing the channel-data into another host recording it.
You can also use another sequencer that can save as .mid file like EnergyXT, energyXT can be used as VSTI in Renoise and can receive your note-data as is, but requires a lot of manual patching afterwards.
There is no native midi export in Renoise yet.