Hello ciro,
I see only two options, calling to the driver directly from CBoard's .dll file. To do this you will need to get all of the functions that are called in the .dll to talk to the board.
Or the CIO-DIO has a set of LabVIEW libraries that are supposed to interface to LabVIEW to give that card an easy interface to program. I do not know anything about these other than what is on CBoard's website.
If you are unable to get either of these to work, NI sells Digital boards that will work with LabVIEW. I hope this helps,
Doug