uses
  Windows, SysUtils, shlobj, ActiveX;

function SHGetFolderLocation (hwndOwnder: THandle; nFolder: Integer; hToken: THandle; dwReserved: DWORD; ppidl:
  PItemIdList): HRESULT; stdcall; external 'shell32.dll' name 'SHGetFolderLocation';
function SHGetPathFromIDListW(Pidl: PItemIDList; pszPath: PWideChar): BOOL; stdcall; external 'shell32.dll'
  name 'SHGetPathFromIDListW';

function PathFromIDList(Pidl: PItemIdList): WideString;
begin
  SetLength(Result, MAX_PATH);
  if not SHGetPathFromIDListW(Pidl, PWideChar(Result)) then
    raise Exception.Create('Odner kann nicht ermittelt werden');
end;

function GetShellFolder(CSIDL: Integer): WideString;
var
  ppidl: PItemIdList;
begin
  ppidl := CoTaskMemAlloc(0);
  try
    case SHGetFolderLocation(0, CSIDL, 0, 0, ppidl) of
      S_OK: Result := PathFromIDList(ppidl);
      S_FALSE: raise Exception.Create('Ordner existiert nicht');
      E_INVALIDARG: raise Exception.Create('Argument ungültig');
    end;
  finally
    CoTaskMemFree(ppidl);
  end;
end;

begin
  try
    Writeln(GetShellFolder(CSIDL_LOCAL_APPDATA));
  except
    on E: Exception do
      Writeln(E.Message);
  end;
  Readln;
end.