I thought you were a scripter?
Thats the absolute basics of RGSS.
Window_Base takes 4 arguments (X, Y, WIDTH, HEIGHT)
When you call it, set the x and y where tou want the window.
it can then be moved through its instance .
ex.
myWindow = Window_Base.new(100, 100, 200, 200)
Creates a 200x200 pixel window at the coordinates 100, 100.
You can then move the window by changing the x and y.
ex.
myWindow.x += 30
myWindow.y = 300