Help script parent - unparent

I have the character jumping to a certain distance already done in Maya. I need to know how to script (transform.parent to the Camera) for it to work on time he jumps and hold on the Camera for 2 seconds, and then (reassign it to the original position transform) by the time he returns (jump back).

frame 0 - 20 he jumps to the Camera, like if he’s hold on over the Iphone camera.
stay holding 2 seconds
20 - 30 frame it jumps back to the orginal plane target position.

it will be necessary to make a new animation in unity, beyond that already exists in Maya, to specify the distance from 3D character to ARCamera within the unity?

i need help in create that script…