A method for introducing instructions/commands within or acting on the content material of a mail run data file. The method comprises the steps producing an object-oriented data file of the mailpiece content material and displaying a visual image thereof to the user. The visual image displayed spatially corresponds to the object oriented data file. Through the use of a graphical user input device, such as a point-and-click input device, the user defines a region of the visual image. Further, the user creates or selects a rule or expression indicative of a desired instruction/command in connection with the defined region. The rule or expression is represented in computer program code and operates a signal processor to perform the selected instructions/commands.