The wealth of functionality in the Excel software package means it can go beyond use as a static evaluator of predefined cell formulae, to be used actively in manipulating and transforming data. Due to human error it is impossible to ensure a process like this is always error free, and frequently the sequence of actions is recorded only in the operator's head. If done regularly by highly paid staff it will be expensive. This paper applies to those spreadsheets which involve significant operator intervention, describes a method that has been used to improve reliability and efficiency, and reports on how it has worked in practice.