In Storyline 360, how do I vertically position a recorded screen video so it is position 0,0?

Greetings all,

Working in Storyline 360, we are creating software simulation training modules. Because our UI requires a 30 pixel block at the bottom of the screen, the screen capture vertical size is 30 pixels less than the slide size (slide size = 1280 x 720;  capture dimensions = 1280 x 690). When the captured screens are inserted on the slides by Storyline, they are centered vertically, so there is space above and below. Now we need to move them up to position 0,0.

How do we adjust the vertical position of the recorded screen captures? I've gone through the tutorials and couldn't find anything that helps (unless I missed it or looking in the wrong place).

Thanks and cheers,
Russell