Defining rigid body group in MCD module

Hi,

I imported a model and defined the rigid groups in "Modelling" module of NX 12.0. Now I want to add pneumatic cylinders, for which I am using Mechatronics Concept Designer (MCD) module but the problem is I cannot see the rigid groups that I created in modelling section, in MCD module. What should I do? Should I re-create the rigid groups? If yes, how can I create rigid groups in the MCD module, because it only shows the option of the rigid body. Any help will be much appreciated.

Thank you