Display own icons when using Cloud Filter API

Question

Hi,
we are developping a sync engine using Cloud Filter API where we'd like to provide the placeholder files with our own icons.
In the Cloud Mirror Sample the icons are selected from shell32.dll but with the comment:

// This icon is just for the sample. You should provide your own branded icon here

To achieve this we expanded a dll named ClientDriveCfApi.dll with our own icons. This dll is part of the solution (And at least I get our own icons offered in Windows Explorer when choosing this dll in a folder's context menu on Properties -> Customize -> Change Icon...)

To get an icon of our own displayed in our application we altered our code from

prop.IconResource(L"imageres.dll,-59");

that displayed the desired icon from imageres.dll to

prop.IconResource(L"ClientDriveCfApi.dll,-1");

for getting our own icon displayed.

But we only get the default icon displayed then.
How can we provide our application with our own branded icon?
Any help would be appreciated.