Thanks for prompt response with ideas. Having a recent version of Cakewalk I don't have the ChannelTools VST so could not try that.
I tried the 'bounce to track' option but it seems it is only available for recorded signals which is not what I'm after as I want a realtime solution.
I managed to achieve what I wanted using the Stereo Control plugin (see link below) on 1 of the tone generator tracks and using the swap channels facility. I then combined the 2 tone generators in an Aux track and then routed that to the scope track. However, not perfect results as I can't get a stable trigger on both channels with the scope VST that I have (J-Scope V1.1). Perhaps someone can recommend an alternative?
http://www.alexhilton.net/A1AUDIO/index.php/a1stereocontrol
I must admit I was a bit surprised at having to use a 3rd party plugin to achieve what I thought was a very basic function. The old days analogue equivalent would be a jack patch panel where you would just plug 1 mono signal jack from 1 tone generator into one stereo channel and the other one generator mono jack into the other stereo channel. I'm sure such a basic routing functionality exists in Cakewalk but I've yet to find it.
Thank you all once again for your help.