How can I import Sets in a new and blank cost element group?

I want to create a cost element group which is independet on the standard hirachy but contains 100% of this data (elelment and groups) to further modify the new Group independet of the standard hierchy.

I exported the cost element group, created a new blank cost element group, imported the data as "set" in the new group.

So now I want to actualy use the set in my blank new cost element group but how?