Thanks again to all who responded. I went ahead and bought the ticket online so there would be no hassle at a window. Before I purchased I emailed Bahn.de and ask to confirm the station. They said the same as you have posted except when I went to book I was offered three choices.
Flughafen
Flughafen Fernl
and Flughafen Regionalbf.
The person responding that the ICE left at :54 iced it for me.
When I booked the departure was for 12:54 so I'm sure I did it correctly thanks to your assistance.
Now, finding the platform will be fun. This gives me four hours if the Lufthansa is on time so there should be no rush.
It's not difficult - you want the "Fernbahnhof", also signposted "long-distance trains". The "Regionalbahnhof", which is underground, is for the local trains. There's nothing else.