VSTI plugins from Nuendo not found in Cubase

I have a version of Nuendo 3 on my computer that I had been using a few years ago before updating to Cubase 5. However when I open Cubase 5 only about half of the VSTI plugins I was using with N3 are now available…and its driving me insane! (One missing for example, is Battery 3, and what I desperately need to use right now!)
I went into Devices/Plug In Information in Cubase and they are not there.
How can I fix this and make them available or create a path?
I am a newbie and not very tech savvy, so any and all detailed and easy to understand instructions would be very greatly appreciated!

Still needing help with this. PLEASE!!!