In fielding some viewer questions, Pim Grooff shows how you can create a virtual object in Cinema 4D using Python.
a quick tutorial on how to create a (basic) Object Plugin.
An object will either create a virtual object in cinema 4d or modify an existing one.
Here, Pim shows the former, walking through how to create a virtual object in C4D, by creating an InTheMiddle4D object plugin. The plugin will create an object in the middle of two child objects in C4D. You can even download the Python Object source for the walkthrough.