Yes, this is doable.

Point Adagio Ledger at last year's data. Go into the Financial Reporter. Load the specification with the current year's budget (which will be last year's). Press F9 to update the column. Copy the column to the clipboard. Paste the column (with last year's figures) onto the financial statement for the current year. You will probably want to disable .SmartSheet and .AutoUpdate to prevent the rows from being refreshed every time you press F9.