Power Query: Access Other Tables at Design Time

So my idea is that as much as possible... do everything in Query Design time.

With that, I simply want to create a composite key but this time around based on another table, so instead of me doing:

         - New Column

         - LookupValue(PrimaryID(other table),ForeignKeyTableWideID(other table),TableWideID(this table))

I'd like to have an equivalent logic in query design mode

        - Add New Custom Column

        - some kind of join???

Dummy PBIX: https://drive.google.com/open?id=0Bw37apQUhEqhdmJ0dTBZbVBuS1E