[Q] [CM10 Theme] Port\land background

I'm new at theming so I've some questions, if who is more expert than me (like everyone lol) could help I'll be very thanksful.
It's possible to set two different backgrounds, one for port and one for land?
If not, what have I to edit for changing the high part of, for example setting (where there are the name and if theme are presents the tabs)?

Please excuse the possible error i did writing.
Thank.