I be honest I cannot remeber how to do this if it is not there as an option. I seem to remember maybe something about editing the ini file but you will have to wait for Gordon to give a more definative answer.
Actually I need this to display PAL res for recording DVD's I could output in PAL res with TV Tool but R4 would not play.....

The DVD's record smoother then too.
But I do question however you graphics card coping at that res?
I do not have card that quick. GF4 ti's 4200 to 4800 and I will get nowhere near that spec.
To run at that res you will need to run the Pbuffers at 2048x2048 for best results (or maybe get away with 2048x1024). I doubt my next card the 6800 Ultra will be be able to run r4 at this spec and regularly get 60fps esp during the more complex transitions and the like.
What res's do you get options for?
Hold on 1920x1200???? That is not 4:3 ratio? Does your video card support that? The 4:3 ratio wil be 1600x1200.
R4 designed most of the time for a 4:3 ratio you are best off sticking to that.