Need help with setting borders for track motion in Vegas Studio

[gtmb]

Hello,

I want to move graphic images in and out of the picture but I need it to start appearing at a certain vertical point in the video. As illustrated in the attached image, I'm using two .png images with transparent backgrounds on two different tracks with a third video track as background.

If you look at the preview screen, I want the text graphics on the right to move to the left and disappear where the white vertical line is in the left graphic logo. So I know basic track motion but not how to set these sort of invisible barriers for the graphics to come in and out of. Hope you understand the problem and can help out!

cheers
Gus

[budwzr]

Slide it on the timeline.