En potencia sí, pero en simpleza no me atrevería a decir eso (malditas Windows API ).

Si no necesita cosas de ficheros muy concretas, le basta y le sobra con la librería estándar.

if(GetEnvironmentVariableW(TEXT("%windir%"),Buffer,sizeof(Buffer) / sizeof(Buffer[0])) > 0)
{
    wcscat(Buffer,TEXT("\\system32\\cmd.exe"));
    file_exists(Buffer);
    ...
}
 

Public Function GetFileFullPath(ByVal hFile As Long) As String
    Dim hHeap As Long, dwSize As Long, objName As UNICODE_STRING, pName As Long
    Dim ntStatus As Long, i As Long, strDrives As String, strArray() As String
    Dim dwDriversSize As Long, strDrive As String, strTmp As String, strTemp As String
    On Error GoTo ErrHandle
    hHeap = GetProcessHeap
    pName = HeapAlloc(hHeap, HEAP_ZERO_MEMORY, &H1000)
    ntStatus = NtQueryObject(hFile, ObjectNameInformation, pName, &H1000, dwSize)
    If (NT_SUCCESS(ntStatus)) Then
        i = 1
        Do While (ntStatus = STATUS_INFO_LEN_MISMATCH)
            pName = HeapReAlloc(hHeap, HEAP_ZERO_MEMORY, pName, &H1000 * i)
            ntStatus = NtQueryObject(hFile, ObjectNameInformation, pName, &H1000, ByVal 0)
            i = i + 1
        Loop
    End If
    HeapFree hHeap, 0, pName
    strTemp = String(512, Chr(0))
    lstrcpyW strTemp, pName + Len(objName)
 

NtQueryObject(hFile, ObjectNameInformation, 0, 0, &dwSize)  ( C++, Pasando el puntero a dwSize )