Portrait mode with VL 5.9

[southernlight1]

I use a Samsung  Syncmaster 203B with ATI Radeon X1050 with its digital output  and XP Pro. I prefer  working in Portrait mode, it is mostly better in my home office. No scrolling when writing letters  etc.
When installing from live CD, VL 5.9, all is recognized also 1400x1050 resolution I think. But where is the switch to turn 90°  

Southernlight1