But i googled it, and a lot of sites said that Dianda was a blend of Deanne (divine) plus variants of Andrea (masculine) and Sandra (protector of man). But don't quote me on it!
(ps the sites i found it on are:
http://www.andythenamebender.com/name-meanings/Dianda.htm ,
http://www.parenthood.com/babynames_searchresults.html?searchName=Dianda ,
http://www.unique-baby-names.org/baby-names/Dianda )