Think the Payware FSUIP interface for FSX too, but not sure.
Other games limited to 32 buttons because they still using old DInput DLL.
A way to use this buttons is through keyboard emulation - that dumb "press joy button to press keyboards keys to do commands in games" that TARGET users love.
The Freeware SVMapper allow you use buttons above 32 to send keypress for games, but dont't recognize axis.