Stereo is always two separate channels in Vegas, even though they're on the same track. Do you mean you want each channel on it's own separate track?
In the pro version you can right-mouse-button click on the audio event, click channels, and then left only or right only. If you can do this in the studio version then that will take care of it for you. Import the audio clip twice on two separate tracks. Set one to left only and the other to right only.