Cities and villages in area hierarchy

Dear developers!
I use the features of OSM for a while, mostly for representing geodata related to subareas of my country (Hungary).
I see that most countries has the following hierarchy :
level 2: country itself
level 4: subregion
level 5: further division of the subregion
level 6: counties
level 7: part of counties ("járás")
level 8: villages and cities
level 9: districts (of capital)

The subareas are well linked to each other with "subarea" typed members. But what I miss is to include villages and cities in this hierarchy.
What is the osm policy about extending member declarations of subareas?
I wrote a program which fetches all the villages, and searches for the correspondent level7 area what they are included in. (earlier I modified the map to link missing admin_centre nodes correctly) If you are interested in, i can adopt the method to other countries, it's fast enough to process the whole world if needed. Hovewer, the last step of submitting informations is still missing.
The final result is now a list of village-subarea id pair I calculated which would be posted somehot to the map itself. I guess I should use the API somehow to this, if you have any simple solution to this operation (only want to add a single member as the following):

member type=relation ref=[village_id] role=subarea

Would say thanks for any help.