Access the active eb instance in vb.net/c#

To Access an instance of EB from an external program it's possible to create a new Instance via

            Aucotec.EngineeringBase.Interop.Application eb = new Aucotec.EngineeringBase.Interop.Application();

        

Now i like to access the active instance (like in VBA) instead of creating a new one.
Can someone help?