Creation of Equipment model/groups using wizard

Creation of Equipment model/groups using wizard

Hi,

I am new to Addins.
I need support on creating Equipment model and group using addin. 
I am able to access already available Equipment model and change it's dynamic property

IEquipmentModel myModel = activeProject.EquipmentModeling[0];
string name = myEquipModel.GetDynamicProperty("Name").ToString();
string newName = "TestModel";
myModel.SetDynamicProperty("Name", newName);

it works. 

but when I try to create models and group using CreateDynamicPropery();

IEquipmentModeling myEquipModeling = activeProject.EquipmentModeling;
myEquipModeling.CreateDynamicProperty("string propertyPath");

I am unable to create it.  Am I doing mistake in propertyPath. How to solve this?