Zoom contacts on Polycom phone

Here is what I am trying to accomplish.

1. Sync Zoom subscribers to the Corporate directory on the VVX 250’s and the VVX450 with the VVX EM350.
2. I would like for the receptionist with the VVX EM350 to be able to click one of the 30 buttons to ring a phone in a classroom. Right now I have 50 Zoom subscribers with extensions and I would like them to show up on the Polycom VVX EM350.