Get the screen coordinates of the object in the projected FishEye image

Hello, I have a setup where the camera view is captured, then modified by some FishEye shader and then projected onto the screen. I want to know the screen coordinates of the object in the projected image on the screen. How can I achieve this? I tried camera.worldToscreenpoint but it only gives coordinates with respect to original image captured by camera. In my case the Fisheye shader is modifying the FieldOfView, So the object is at different position on the screen compared to without FishEye effect. Is there anyway I can get the screen coordinates of the object in the projected FishEye image?