This event type enables commands to run when an app starts up. This works in both Word, PowerPoint and Excel. There are two kinds of events depending on whether it should run every time a program is opened or only once. 

Event on start up

The following event makes sure that commands run on every start up. 

<event type="BaseExtensions:OnAppStartUp">

Here is an example:

<event type="BaseExtensions:OnAppStartUp" showInWord="false" showInExcel="false">
  <Cmd case="BaseExtensions:AlertOk"/>
</event>

This will prompt the user with a dialog box every time PowerPoint is started. 

Event on start up once

The event below ensures that commands only run one time. This can be in intervals. The event name can be continued by any form for characters, but it needs to start with OnAppStartUpOnce. For instance, OnAppStartUpOnce2, which will run the command the second time only.  

<event type="BaseExtensions:OnAppStartUpOnce">