Is there a way to convert a DS arc into a polyline in order to fillet the two? Currently when filleting a polyline and arc I get the message: "Cannot fillet between these two entities"

In Autocad I'd need to edit the arc (Type PEDIT) and click the arc to convert it to a polyline first. Is there a similar command in DS? If not there ought to be as it's a common need to fillet these types of objects.