Simulation provides some utility functions to facilitate common tasks, e.g., running command line and text file replacement. Those utility functions are encapsulated in Opaque Behaviors under SimulationProfile::library::utils as shown in the figure below.
Note
If the SimulationProfile package is not visible, click 
in the Containment tree pane and select Show Auxiliary Resources.
CommandLine, one of the utility functions of Simulation, is used through Opaque Behaviors in SimulationProfile::library::utils (shown in the circled area).
You can use those Opaque Behaviors by dragging them to the Activity diagram and setting parameters as described in the Opaque Behavior section. Simulation also provides a few samples using the Activity diagram in the utils package. As displayed in the figure below, you can use WindowsCommandLine to open Notepad on Windows.
Using WindowsCommandLine to open Notepad on Windows.
From the following figure, you can use TextFileReplace to open the build_me_a_HAB.ses file and replace $press_tunnel_len$ with 2.0. See also the UsingCommandLine.mdzip built-in sample in Simulation on the Welcome page.
