如何将此代码转为使用跨窗口选择而不是选择两个点？

Question

此代码目前允许通过选择 2 个点来创建一维线（距对象 200 米）和二维线（距一维 100 毫米）。但是，我希望它是一个交叉选择，而不是它会自动为交叉选择（当鼠标从右向左拖动时）会触及的任何对象创建尺寸线。

            (defun c:d200 ( / pt1 pt2)

            (prompt "When asked points can be picked upside down to imply outward.")
            (setq pt1 (getpoint "\nSelect 1st point on left "))
            (setq pt2 (getpoint "\nSelect 2nd point on right "))
            (setq ang (angle pt1 pt2))
            (setq pt3 (polar pt1 (+ ang (/ pi 2.0)) 200))
            (command "dim" "Align" pt1 pt2 pt3 "" "exit")
            (setq pt3 (polar pt1 (+ ang (/ pi 2.0)) 300))
            (command "dim" "Align" pt1 pt2 pt3 "" "exit")
            (princ)

            )