WDK: Casting PVOID to PWCHAR (C to C++ conversion)

I am experimenting with a Windows driver and working with Microsofts driver code examples (Minispy to be exact). Unfortunately, i am pretty new to C++ and especially driver development.

While translating the user-mode application from C to C++ (most parts work very well by now), i encountered an interesting cast:

CHAR buffer[1024];
PINSTANCE_FULL_INFORMATION data = (PINSTANCE_FULL_INFORMATION)buffer;

hResult = FilterVolumeInstanceFindFirst(VolumeName,
        InstanceFullInformation,
        data,
        sizeof(buffer) - sizeof(WCHAR),
        &bytesReturned,
        &volumeIterator);

PWCHAR filtername = PVOID(PUCHAR(data) + data->FilterNameBufferOffset);
filtername[data->FilterNameLength / sizeof(WCHAR)] = L'\0';

if (_wcsicmp(filtername, MINISPY_NAME) == 0) { ...

This part of the code delivers an compiler error C2440: Cannot convert from PVOID to PWCHAR:

filtername = PVOID(PUCHAR(data) + data->FilterNameBufferOffset);

The code worked perfectly fine in C, but C++ won't cast that void pointer "array" to PWCHAR.

I tried for hours now, i could not get it to work. Any ideas?

Many thanks!

For reference:

The PINSTANCE_FULL_INFORMATION struct:

https://msdn.microsoft.com/de-de/library/ff548185(v=vs.85).aspx

The compiler error C2440:

https://msdn.microsoft.com/en-us/library/sy5tsf8z.aspx