Is there a way to import a reference set directly from a column in an Excel sheet?

I have two entities where i try to import a list of entities which reference one or more MainEntites.

I have a simple export that shows Name and a list of Codes (reference set) to a main entity.

In the Template the Code is set to be Reference to MainEntity.Code (key for only assiciated entity with Ignore if not found).

The problem is that Excel Import uses the whole string as Key ("1,2,3" [Key] instead of each "1"[Key], "2"[Key] and "3"[Key]) and then ignores it.

I managed to get it to run if I use "Append" on the reference and then do one Code-reference per line, but that is not what I want.