If the variable does not exist, just return.
[wine] / dlls / dpnhpast / dpnhpast.spec
2003-07-30  Alexandre JulliardMake the DllRegisterServer, DllRegisterServerEx, DllUnr...
2003-04-08  Rok MandeljcAdded stubs for dpnhpast and for all the dmusic dlls.