I am trying to operationalize a predictive model that calculates a new
value based on the preceding value.

I have all the necessary coefficients stored. I have factors
designated "past" and "current." When new data comes in, I'll input it
into "current" and shift previous "current" to "past." Then, previous
"past" is no longer needed.

I want to write a macro that by clicking a command button, will copy
data from "current" into "past."

For example, $38.99 is in cell E30. After clicking a command button, I
want that copied into cell F30.

I have some experience with VBA, but it's limited. Any help would be
greatly appreciated.

Thanks a lot,
Andrew