Better line specific calculations

If I compare calculated columns to Excel, Spotfire is better insofar that a calculations that is consistently applied to a whole column is not prone to the copy/paste errors inherent in Excel. However the kind of expression that uses the value calculated in the row above is difficult to replicate in Spotfire.

Imagine a column of numbers, A. And a column B whereby Bx=Sum[A(x-5):A(x-1)]

ie when we are on line 5, B6=Sum[A1:A4] and when we are one line 10 B10=Sum[A5:A9]

You can sometimes work around this by adding an artificial order column and a complex OVER statement, but this becomes quite cumborsome relative to the expression in Excel, which increments any line position by 1 on every line the expression is dragged out to unless it is preceeded by a $