Setting global rotation of a vector using a quaternion in THREE.js

I would like to set the absolute global rotation of a vector using a quaternion.

Let's say I have a function f(v, q) which rotates vector v to quaternion q.

THREE.Vector3 has a .applyQuaternion function which applies a rotation to a vector, but this is a relative rotation. For example, the function call f(f(v, q), q) will apply q twice. Instead, I would expect f(f(v, q), q) = f(v, q) since q is the absolute rotation of the vector.

I know that I can compute some deltaQ = currentQ.premultiply(q.inverse()) and then call .applyQuaternion, but I don't know how to query the currentQ, or the current rotation of the vector, so that I can "undo" it and apply the new quaternion.

Thanks for any help!