Access to the registry in a WDM driver

Hello everyone,does anyone know how to access to the registry in a WDM driver. I know there are
some functions in the DDK document such as ZwCreateKey(),ZwOpenKey(),ZwSetValueKey(). But I
still don’t know how to use these functions. For example, I want to create a subkey “RGDR” in the
“HKEY_LOCAL_MACHINE\Software” directory. And then set a REG_DWORD value under that subkey. How
can I implement this? Can anyone give me an example? Thank you very much.
b???.???????&?v?'?ׯj?.n?Qyȩf??]?:.?˛???m??֛???zf???%y?ޞ?^?˛??^r*Lzfެ?…???l??ܢ