In the Project window Inspector add Direct Routing tab. Then click to the icon next to the Direct Routing tab name to enable the Summing Mode. Open the Direct Routing tab and add up to 8 outputs to the slots.
ok was really easy in the end, worked it out myself.
hit F4 > outputs tab > hit add bus > select stereo bus > direct route audio to that bus (dunno what you were on about with summing mode, but thanks for reply anyway)