Getting the Windows Control Panel's virtual folder - winapi

Question

Why would GetPath always return E_FAIL when querying FOLDERID_ControlPanelFolder? Other FOLDERIDs actually do work:
HRESULT hr = S_OK;
*path = '\0';
LPWSTR pwcPath = NULL;
CoInitialize(NULL);
IKnownFolderManager *pFolderManager = NULL;
if ((hr = CoCreateInstance(__uuidof(KnownFolderManager), NULL, CLSCTX_INPROC_SERVER, __uuidof(IKnownFolderManager), (LPVOID *)&pFolderManager)) == S_OK)
{
IKnownFolder *pControlPanelFolder = NULL;
if ((hr = pFolderManager->GetFolder(FOLDERID_ControlPanelFolder, &pControlPanelFolder)) == S_OK)
{
hr = pControlPanelFolder->GetPath(0, &pwcPath);
if (hr == S_OK && pwcPath)
{
int nSize = wcslen(pwcPath);
WideCharToMultiByte(CP_ACP, 0, pwcPath, nSize, path, nSize+2, NULL, NULL);
path[nSize] = '\0';
CoTaskMemFree(pwcPath);
}
pControlPanelFolder->Release();
pControlPanelFolder = NULL;
}
pFolderManager->Release();
pFolderManager = NULL;
}
CoUninitialize();
(Yes, I stumbled upon this question but I don't have need for all that enumeration stuff.)

Answer 1

The Control Panel has no directory path because it does not exist on the disc. You can get its PIDL, and even a Desktop Absolute Parsing "display name" (via GetShellItem and GetDisplayName), but not a directory path.

Answer 2

Reason why I needed the path was that I wanted to open the controp panel with a ShellExecute "open". I now execute the control panel program directly, with the benefit of being able to select the desired applet right away (in this case "Sound"). I hope it's not too pretentious that I post this as answer:
char controlpanelpath[2000];
UINT controlpanelpathbuffersize = sizeof(controlpanelpath);
int actualcontrolpanelpathsize;
if (actualcontrolpanelpathsize = GetSystemDirectory(controlpanelpath, controlpanelpathbuffersize))
{
char *parameters = "\\control.exe mmsys.cpl,,0";
if (actualcontrolpanelpathsize + strlen(parameters) < controlpanelpathbuffersize)
{
strcat(controlpanelpath, parameters);
WinExec(controlpanelpath, SW_NORMAL);
}
}