You can use the key attribute in your After Effects Expressions to work with time, index, and value properties of a keyframe. In this video tutorial, I demonstrate an expression using the key object properties of time and value to make a shape layer meet with a text layer — no matter what changes are made to the text layer’s keyframe time or position value.
Here are the expressions used in this example. Keep in mind the text in all caps (with a question mark and underline) needs to be changed to suit your needs.
textTime = thisComp.layer(“LAYER NAME?”).transform.position.key(WHICH KEYFRAME?).time;
textValue = thisComp.layer(“LAYER NAME?“).transform.position.key(WHICH KEYFRAME?).value[WHICH VALUE?];
ease(TIME?, TIME START?, TIME END?, VALUE START?, VALUE END?);