Make light dynamic shadows only

Is there a away of making a light cast shadows for dynamic objects only.

At the moment I think -

              static lights don't
              Stationary light, will cast shadows on dynamic and static objects - but ONLY if cast on static objects is enabled.
              movable light, behave like stationary lights in this respect.

If I have my static objects using static lights… I now want movable objects to cast their shadows… but I seam to only be able to do this my adding a stationary or movable light that’s going to effect my static lighting as well !

Any ideas ?