Expose SpreadSheet : ^&_
...

SpreadSheet->
 'A1' = '= Sum [A2..A500]'
 'B1' = '= Sum [B2..B500]'
 'C1' = '= Sum [A2..A500], Type=WMA, Direction=Up'
 'D1' = '= ([B.] * [C.]) / [A.]'
;