You have two options when creating custom commands that run programs. This page describes each.
If you press Win-r, Windows opens the Run Command, where you can enter the name of an executable to run. You can build commands that perform the steps for you:
You can find example commands in the "windows" mode. Commands that start with "open" use this approach.
  You can create commands that use the execute
  function
  to execute an application or a command line executable.
  You can optionally provide utterance arguments as flags to the executable
  and type the results returned from the executable.
This function can be useful for:
execute function
    in custom commands to call your executable.
  For example commands, you can see the "example scripts" mode, which is inactive by default.
  One of those commands uses a three-characters.exe
  command line executable.
  You can find this executable, as well as its source code, in the
  three-characters directory in the
  Utterly Voice application directory.