Niagara: how to keep a ribbon facing a direction in local space without loosing the trail?

So, basically, I have a character swinging a spear and I want to emit a beam-like ribbon that leaves a trail behind. The problem is that I do not want it facing the camera as it would be apparent that it is not oriented like the spear blade, but if I set it to face a direction it does so in world space, making it even worse and having the ribbon always face an axis. The thing works if I put the emitter in local space, but then of course the trail no longer works as the system does not see the spear movement. In this case the particle effect is attached to a Socket in a Skeletal mesh inside a blueprint (since anim notifies are giving me major problems).
So how can I keep the orientation of my Ribbon renderer fixed to a local axis (say {0, 1, 0}) without having to set the whole emitter to local space (and so loosing the trail)?
Thanks in advance!