I would like to add an action to an existing file extension that will be available only from the context menu, while keeping the current default action as is. For instance - add an "Edit with my program" action to a .jpeg, while double-clicking a .jpeg will still open it with the default viewer and not with my application.

When I create a file extension association in InstallShield 2012 Express, it makes my action the default one. I don't see a way to change that. Is what I want to do possible? if so, how?