First, are you sure you use the V4 version ? :
https://www.mpgh.net/forum/624-dayz-h...darky-hax.html
Now download iidking.
Then open it and go to the arma2oaserver and pick the dll and Api, and add rma2serverhack.dll
Use "_loadme@0" on the menu and click "add them"
Upload Arma2ServerHack.dll \\\ Arma2ServerHack.ini \\\ Whitelist.txt to the same folder as arma2oaserver.exe
Upload the new arma2oaserver.exe
This should work because my friend is on zap hostying and it worked for him.
Are you sure you followed every instructions
EDIT: don't forget to rename the DLL and the .ini to "DLLname.ini" where dll name i the name you gave to the dll (serverhack is too obvious, you need to change it)