Question Where to start on locking target reticle for throwing an object?

I've got a multiplayer game in process with players at desks with no locomotion. One of our powerups is a throwable item, which I'd like to lock on to desk locations as you aim the motion controller. Instead of implementing a physics-based throw, which would create struggles with accuracy, I just want the player to see when their reticle is locked on to the right desk, and be able to press trigger to initiate the throw.

I'm really not sure where to start with this. One major question is how to create a simple parabolic trajectory for the thrown object that hits the chosen target every time. The other part is figuring out how to track continuous motion controller data as the player scans over targets, and causing the reticle to "lock" on to a target... Thanks in advance for any best practices for implementation.