How about asking your parents first? Otherwise, it could be from
Lana with a the prefix De. I am not sure what
Lana means though. On this site, it says it is short from
Alana or
Svetlana, but my accounting professor's first name is
Lana (pronounced lah-nah) and she is middle-Eastern (will not say exactly from where :(. So my guess is,
Lana could be short from a middle-eastern name as well.
Hope this helps a little