[Game] HotKeySet doesn't work in ArmA 2: OA

Hello,

I need support because I didn't find how to active binds key in game ArmA 2: OA with function HotKeySet!

I tried with:

HotKeySet("{F1}", "_My_Function") ; F1
HotKeySet("{a}", "_My_Function") ; a
HotKeySet("{!a}", "_My_Function") ; ALT+a
HotKeySet("{+a}", "_My_Function") ; SHIFT+a
HotKeySet("{NUMPAD0}", "_My_Function") ; Numpad 0

My problem is not my function because if I call directly with:

While 1
   _My_Function()
WEnd

result does work...

PS: I tried HotKeySet in another games and does work but not in game ArmA 2: OA