Hello Peter, thanks for your answers.
I firstly tried what you explained but got stuck with the amount of points needed on the curve to achieve a rain effect. The group node takes forever to cycle through all the points generated. That's why I was looking for a way to only evaluate the points close to the camera, and dynamically.
I solved this first problem by using the voxelGrid node in worldSpace, parented to the camera. It creates point on the fly, and with a 3D texture (constant in worldSpace) I could easily randomize the position.
I'm now fighting with the motion blur because of the dynamic point generation but will share a setup once fully usable.