Starting rendering point of eyeTexture ?

After integrating oculus rift in unity, we are using webCamTexture class for grabbing feed from 2 cameras. Since view in Oculus is zoomed in, we scaled texture (Virtual texture scale = 2) but texture in Oculus is being drawn in bottom left part. Is there a way to set up a starting rendering point of eyeTextures. Problem is shown on picture below. Without using GUI functions.