.Use of OS native command
      Select option 6 on MENU screen.                     Chapter-(2)
      Or using DOS command prefix(>) create child Shell   Chapter-(5)
      SPAwn cmd is to submit asyncronously windows GUI application.

      If environment valiable such as PATH is required
      Use SET/EXPort command.
      ::xe.env is read to set environment variable at xe start if exist.
      if xe___.env(___:os type, ex. xewin.env) is exist this
      is used as alternative.