What is a COM (Component Object Model) Add-in?

COM (Component Object Model) Add-in

When you speak of COM add-ins, the letters COM stand for component object model. The component object model is a Microsoft software technology that allows software components (like Microsoft Office programs) to Communicate. For example, a form of COM technology is used to allow Word documents to link to data in Excel spreadsheets.

COM add-ins provide a way to create and use program code as a DLL (dynamic link library) file. This means that the COM add-in module could be shared by multiple Office programs. You can create your own COM add-ins, but doing this requires the ability to program in a language that supports ActiveX controls. For advanced work, the installation of a software development environment like Visual Studio may be required. Often, COM add-ins may involve user forms and ActiveX controls.

To access any available COM add-ins, display the Office menu, and then click the Excel Options button at the bottom of the menu items to display the Excel Options window.