You need to be connected to the internet in order to activate the software and install the additional content.
So there is no possible way to get the content except connect the computer to the internet (Which I cannot do) ?
I'm not sure why you can not connect your computer to the internet (It would sure be much simpler) -- but that said:
Yes, you can download all content to your internet-connected computer by going to, say, the Tools/Movie Menu workspace, right-clicking on a template and selecting Download All.
Once you've done, so you'll need to copy the entire DVD Templates folder from that computer to your other.
You haven't advised us what operating system you're working on so I can't give you specifics other than saying that, in Windows 7 or 8, this file is located in C:/PROGRAM DATA/ADOBE/PREMIERE ELEMENTS/12.0/ONLINE/DVD TEMPLATES.
On a Mac, this folder is in HD/LIBRARY/APPLICATION SUPPORT/ADOBE/PREMIERE ELEMENTS/12.0/ONLINE/DVD TEMPLATES.
If you've downloaded the other additional content also, you'll find them in the other folders in that ONLINE directory, next to the DVD TEMPLATES folder.
You will still need some sort of internet connection -- even if it's a temporary one -- to activate Premiere Elements 12 on this computer though. I don't know of a way around that.