How to access a scenecapture2D actor from SlateRHIrenderer.cpp?

My main goal is to display another camera on the monitor (instead of the mirror view) when using the htc vive.
I’m trying to modify the engine to replacing the mirror view with the rendertexture of a scenecapture2d actor.
The display of the mirror view seems to be driven by the function DrawWindow_RenderThread in SlateRHIRenderer.cpp

Unfortunately, I can’t access any object in the scene from there.

GEngine->GetWorld()

is always null.

Do you know a way to get a reference to my scenecapture2d actor?