How can i add camunda formdata on other properties?

I use angular, properties panel and

I have a DataObjectReference where I want to display the Form fields in the properties panel as it is done in the startevent or the usertask.

I already extended the camunda moddle descriptor (I use a custom one) so that the elements are within the bpmn. Unfortunately, it isn´t shown in the properties panel yet.

I know how to add custom properties (e.g. a text value or something like that). But I´m not sure how I can add the existing Form field group to the bpmn:DataObjectReference element

Edit: I do not want to recreate all sub properties of the form fields of course