Yes, you sure can. But the best conversion method is simply using your keyboard. Load the midi file into the Genos and then record the midi file to your computer using a DAW software program such as Sonar or Audacity, etc. Once you finish recording the song then you can save the audio file as a .wav file. In order to use the .wav file for an audio linked Multi-pad on the Genos the .wav file must be 44.1 kHz sample rate, 16 bit resolution. The Genos Reference Manual Page 54-55 explains the steps in sequence to achieve a desired result.
PS: You can also edit the .wav file to your personal preference beforehand using an Audio Editing software such as Wavosaur or Waveshop, etc.
Mike