A computer programme product (10) for the configuration of a user-specific product (12) is stored on a mobile computer (2) and has a virtual library (14) with a plurality of selectable virtual components (16) for the compilation of a virtual model (12M) of the product (12) which can be shown on a display (4) of the mobile computer (2), wherein product information (I) for the creation of the actual user-specific product (12) is derivable on the basis of the components (16) selected for the displayed virtual model (12M). According to the invention, at least one functional device (36) is provided on the mobile computer (2), the device being controllable by means of touch operation of the virtual model (12M) on the display (4).