Hi,
one simple trick you can try is to replace the drum instrument with, for instance, a piano. Play both hihat zones, and check if both generate a sound from the piano.
You can press record, and doubleclick the midi region, so that you can see what note corresponds with the front end. Then, you can assign a sound to that note in either EXS24 or Ultrabeat. Or you could get into the settings menu of your V Drums, and change the note of the front hihat to an appropriate note.
Mind you, there's one thing that Ultrabeat and EXS24 don't "hear": the position of the hihat pedal. When you move the hihat pedal, Controler data of type CC#4 is sent to the sequencer. A drum plugin like BFD does react to CC#4, though.
Regards,
Jaap