Adding custom entity in existing device


I have virtual fan created in edge drive of Smartthings.
I brought this device from ST to HA with ST integration.
Even though physical actual fan support oscillating function, virtual fan has no control button(or entity) to control oscilating.

So I want to custom entity for oscillating in the virtual fan from ST. Is it possible?
Or, Can I make additional virtual fan having oscillating entity, and mirroring existing virtual fan brought from ST by template fan code??