Jim, Are you aware of the Excel syntax for range-based calculations? The dot product in Excel is `=SUM(A1:A10 * B1:B10)` for two ranges 1..10 but you need to do a Shift-Ctrl-Enter to invoke it (same as `=SUMPRODUCT(A1:A10, B1:B10)` but w/o the Shift-Ctrl-Enter). A convolution is a running dot product on two ranges with the range endpoints shifting along the timeline, but with one of the ranges reversed in direction. The rest follows from this, as it will depend on how your data is arranged.

edit: As convolution has been given greater awareness via NN and machine learning applications, you can find other algorithms, see https://towardsdatascience.com/convolution-a-journey-through-a-familiar-operators-deeper-roots-2e3311f23379