This far, it is just a case of returning values from a column by index, no lookups are needed.
I used a named formula 'k' to create the table of indices (shown on the worksheet for info only) = SEQUENCE(1, numPeriods) + offset*SEQUENCE(numCodes, ,0)
The table is then = INDEX( Actual, k )
The value, 9, of 'offset' is the spacing between tables.