Sorry, my first reply was misleading.
I have done it using an effect and placing this in the world, not a rela texture.
I've played with CoD2 shaders several years ago, the only thing I managed to get to work was changing the speed of the scroll-texture on xmodels, as far as I can remember. Not even the yellow-pulsating glow on objective-textures changed colors. I gave shaders a couple of hours/days to try to modify them and getting the CoD engine to accept them, but I did not 'understand' them well.
CoD4 got those TV's that display a short video, I remember recreating these without much success.