Yes, with the help of the Door library.
Main.gamewindow should match the name of your GameWindow object.
obj is an Object object.
Code:
obj.New1(False)
obj.FromLibrary("Main.gamewindow", "_gw", B4PObject(2))
obj.SetProperty("Left", 20)
obj.SetProperty("Top", 100)
obj.SetProperty("Height", 50)
obj.SetProperty("Width", 77)
obj.SetProperty("Visible","false")