A system for adding functions to an existing application program executing in a computer system having a graphical user interface that includes a clipboard. The invention displays menu options either on an added menu within the application program or on a menu separate from the application program. The invention intercepts communications between the operating system and the application program and determines when the user is invoking one of the added functions. Simulated user input commands are issued to the operating system to capture information from the application program to the clipboard. The information in the clipboard is processed to provide additional features such as on-the-fly spell checking or translation and the modified information is replaced in the application program by transferring from the clipboard using more simulated user input commands.
16 Claims, 7 Drawing Sheets