SETSCREEN  GuiFile ScreenName

This will reset the name of the screen the GUI should open on.

If the window is already open, you will have to close it and reopen it
in order for the new screen to take effect.

If the screen is not found, the GUI will open on the Workbench (if available)

To state the "Front most Screen" you can give an '*' (asterisk).

See also the  Screen  global command.