How to import only New Item

Hello Sir,
I have created multiple company. All company will use same item (code,Name etc). So every time I open some new item in one company then i need to import all new item in other companies. But we have many many items in different item groups so it is not easy to track new item that was created. When I import all items from the first company to other company then all items added in the ltem list. That way there apears multiple item with same item code, name etc. Is there any way that when I try to copy all items from other company then only new items will be added and the other items which already present in the company will not be added.

Please help. This is important for me…

Not currently