move object in a certain direction

I am controlling the position and orientation of my object with a 6DOF device. I want to simulate penetration inside an object when getting into the object.

So the idea I had was to store the position and orientation at the moment of touching the object (lastPOS, lastROT) and I want to continue reading the position in the Y axis from the device and re-calculate the positions of X and Z so as to show that it is moving in that direction (no matter which orientation or movement the user does with the device, I will just consider how much it moved in Y and visually show it is getting inside the object in the direction stored when touching it).

I am having problems getting a working solution, does someone has an easy way to do it?