You are right, for a dvSwitch portgroup it has to be done a bit differently.
Have a look at my dvSwitch scripting – Part 2 – dvPortgroup post.
It doesn't show how to do this during a clone operation but it shows how you can connect a dvSwitch portgroup to a guest.
If you want I could add a new post to my dvSwitch series on how to do this during clone operations ?
Thanks for the pointers. I think a new post could help a lot.
It works great. I did it nearly the same way using the information from your previous blog post.