I use propellerheads rebirth for fun to make songs and I also have a real 303 that a would like to load with songs from rebirth so that I can write a song in rebirth when I'm on the go with my laptop and then export it to a real 909 and real 303 in my studio. To do this it would be enough if I could export for instance the MIDI track of the 303 presets. Is there a way to do this?
ReBirth does not have any facility to export MIDI from its internal patterns. Which is too bad, really, since it'd be really cool to export from it to hardware devices like you have.
Fortunately, the data in those patterns is relatively simple, so it's conceivable, albeit certainly not efficient, to copy it over by hand.
Some people have made printable preset sheets for those devices (here's an example for a 303) which can somewhat help with this, but they still won't capture modulation over time very well and of course they're not automatic.