How to convert model from Bead type to Atom type?

Hi.
I'm currently calculating the Bead model. For example, I would like to consider such an interface(A|B).
ex:
|-----|
|  A  |
|-----|
|  B  |
|      |
|-----|


I would like to do a Dynamics calculation with a large-scale Bead model first, and then consider medium-scale characteristics with Forcite.
This requires a conversion from the Bead model to the Atom model.
What should I do?