Programmatically selecting integrated graphics in nVidia Optimus

There are many questions and answers about how to select nVidia discrete adapter on runtime on Windows platform. The easiest way is to export a NvOptimusEnablement variable like this:

extern "C" _declspec(dllexport) DWORD NvOptimusEnablement = 0x00000001;

I have the opposite requirement. I need to set the Integrated graphics in runtime for my application, no matter what is the Preferred graphic processor in NVIDIA control panel. This variable is not suitable for this. How can I make this?

How do I change my Nvidia Optimus settings?

Manually Configure OptimusRight Click on your desktop. Click NVIDIA Control Panel. Click Manage 3D Settings on the left menu. Click on the Preferred graphics processor drop down menu under the Global Settings tab.

The code under sop - setoptimusprofile registers an application profile so the driver automatically selects the discrete card for the specified application, maybe you can change it so that it uses the integrated one?