yes, you can send midi. you will have to create a loopback midi device for that.
on windows you’d use something like loopmidi http://www.tobias-erichsen.de/software/loopmidi.html
on osx this is built-in, if you didn’t delete it you should have a “iac driver” virtual device (create one in the “audio midi setup” application that comes with osx)
once you have that:
- in logic, enable midiloopback/iac driver as output device
- create a pattern that sends midi CC signals on midi channel 1, e.g. create a pattern that sends CC20 on channel 0
- in oscistudio, select the midi loopback/iac driver as midi input on the start page and press start
- right click any slider and select “Add midi mapping”. Enter the CC number from step 2
with that you should be all set.