要在ecilisp中創建一個計算器窗口，你可以使用GUI庫，比如Tkinter。以下是一個簡單的示例代碼，展示了如何創建一個簡單的計算器窗口：

(use-package "tk")
(tk-init)

(defparameter *calculator-window* (tk-toplevel))
(tk-title *calculator-window* "Calculator")

(defparameter *display* (tk-label *calculator-window* :text "0" :font '("Helvetica" 24)))
(tk-grid *display* :row 0 :column 0 :columnspan 4)

(defun update-display (text)
  (tk-config *display* :text text))

(defun on-button-click (button)
  (let ((text (tk-cget button :text)))
    (if (string= text "C")
        (update-display "0")
        (update-display (format nil "~a~a" (tk-cget *display* :text) text))))

(defun create-button (text row column)
  (let ((button (tk-button *calculator-window* :text text :command #'(lambda () (on-button-click button)))))
    (tk-grid button :row row :column column)))

(loop for i from 1 to 9 do
     (create-button (format nil "~a" i) (floor (/ (- i 1) 3) 3) (mod (- i 1) 3)))

(create-button "0" 3 0)
(create-button "+" 1 3)
(create-button "-" 2 3)
(create-button "*" 3 3)
(create-button "/" 4 3)
(create-button "=" 4 0)
(create-button "C" 4 1)

(tk-event-loop)

運行這個代碼后，將會創建一個簡單的計算器窗口，你可以點擊按鈕來進行基本的數學運算。你也可以根據自己的需求來定制窗口的樣式和功能。