You're best bet is to talk to the developer. They provided contact information in the VI. Here's a copy of the info:
This vi is written by Pavel Charny
"Automated Control Systems"
Moscow, Russia
contact: Sergey Krasnishov
mmike@glasnet.ru
acs1@aha.ru
If you can't get the information from them, I would recommend searching the web for joystick source code. I bet someone out there has some code they're sharing.