Problem between diaphragm and embeded region in ABAQUS

Hello every one,

I am modeling a core (C shape) subjected to lateral load. I used embeded region constraint to contact steel bars and stirrups to the solid core. Then i want to apply the load at one end of core, but i need to contact all points in this end with a diaphragm to take the effect of the slab which aren't modeled. But i thing that ABAQUS doesn't permit to use two constraints at the same point. So what can i do to constrain the steel bars to core and also to constrain all points at one end with a diaphragm.

Thanks in advance