With a corner window I am using two curtain tracks?

I do not think it possible to do what you wish to do - each individual curtain panel - the left one and the right one - will need to have turn round wheels for the cord - either at the place where the rails butt together (ugly and not practical) or at the extreme end of the other rail - not so ugly but just as impractical

Curtain draw cords are a continuous loop - pull in different up/down directions for opening and closing. To do as you wish will require two loops - one loop for each curtain.

Draw cords going around bends in the tracks are also very difficult to achieve - you might do well to consider good quality tracks and conventional opening and closing.

You might try to draw it out on the back of an envelope - the route of the cords - and see the impractical nature of it.

Good Luck...
November 2015