would look something like this.
If the polyline is CCW
+dist is offset out
-dist is offset in
(if (setq SS (ssget "_X" '((0 . "*POLYLINE") (70 . 1) (62 . 5))))
(foreach ent (vl-remove-if 'listp (mapcar 'cadr (ssnamex SS)))
(setq obj (vlax-ename->vla-object ent))
(vla-offset obj Distance)
)
)
I would suggest either using color coding or using different layers for the direction of offset. like the perimeter is blue for offset in. green can be offset out.