Solution
The Application Manager (ApplicationMgr) is an ActiveX object that is actually part of the TestStand UI Controls ActiveX server. To access a reference to the application manager object, use the following Expression:
RunState.Engine.GetInternalOption(InternalOption_ApplicationManager)
To interact with the application manager object, use an ActiveX Action Step. In the image below, the step is used to access the Executions property. The same procedure can be used to access the other properties and methods of the Application manager Object. Refer to the NI TestStand Help: ApplicationMgr topic for complete documentation on available properties and methods.