This AutoLISP code used to select point objects within a select circle.
The code used "ssget" command with "WP WPolygon" Lisp method.
The selection circle is built with a series of lines.
The dialog box displays:
After the selection, the screen displays with the command "grvecs" the select circle set (color red) and the points of the selection (color blue)
The center of the selection is green color.
The download file (zip) contains an AutoCAD file with sample points.
The AutoLISP script (command "Load_dlg") and the DCL file to the dialog box(see above imagine).
The demo of this software is provided FREE by cadoptimize.com