VRay Displacement/Different Mapping?

[Schnupps]

I´m currently working on an animation, which requires the VRay Diplacement to work on multiple mappings.
For the Displacment I´ve got a mix map with two maps which use the same mapping channel (a unwrapped uvw) and the mix map which should use one projected uvw mapping, since the geometry is supposed to "slide" underneath. But it seems that Vray Dips. just works on one channel (the one I chose in it´s rollout).
Is there any way I can still get this to work?

Thx Schnupps

[RErender]

You'll need to use 3D Displacement and the "use obj mtl" which will then use the result of the displacement slot in the material.