Engineering Template "To Replace"

Hi everyone,

As you can see in the title I'm looking for some information about how to use the "Replacement" of used Engineering Templates. I've seen that when I create an Engineering Template I have this option and it might be very powerful but I don't manage to make it works. Does anyone has got some experience or informations about how to use it?

In addition it would be interesting to know if there would be the possibility to use it also in EKL...

Thanks in advance