This is not too hard, but just when you get used to doing Adobe products, they change something. My fault I am sure for just doing what I thought was right.. Trick is, use the OEM.exe NOT the setup.exe

So, CMD line to install...

"%~dp0oem.exe" /UL1033 /V"SERIALNUMBER=XXXX-XXXX-XXXX-XXXX-XXXX-XXXX COUNTRY=242"
IF NOT ERRORLEVEL 0 Exit %ERRORLEVEL%

Also, put the Application overrides into:

EO12AMTLibSupport
PRE12AMTLibSupport-64

I think there is enought notes about creating those...

The next thing you're going to askis ... what about that Adobe Log in box that appears when you launch the app??
You have to download the Adobe_prtk.exe kit. I could put the output of adobe_prtk.exe /? here, but you guys can do that...

Then create an XML for the serialisation.
"%~dp0adobe_prtk.exe" --tool=VolumeSerialize --generate --serial="XXXX-XXXX-XXXX-XXXX-XXXX-XXXX" --leid="V7{}PremiereElements-EMT12-Win-GM"

That creates an XML, then you need to apply it:
"%~dp0adobe_prtk.exe" --tool=VolumeSerialize --provfile="%~dp0prov.xml" 

However, an Adobe online log in still appears, but you can use the app with out logging in.

It is possible to do the online reg thing with the tool, but I have left that for the client site, they have a single user ID they use for these purposes, I will let them and their legal team have that discussion.

One more thing...

When you launch the app, it goes to a wizard, asking users to choose a view type...
Wizard, organizer or the main app (premiere). The key below sets it to the main app

[HKEY_CURRENT_USER\Software\Adobe\Premiere Elements\12.0\WelcomeScreen]
"QuickLaunchApp"=dword:00000002