Range.InStory (Word)

True if the range to which this method is applied is in the same story as the range specified by the Range argument.

A range can belong to only one story.

InStory (Range)

Range: Specifies the range that this method uses to determine if it is contained within the specified Range object.

Set Range1 = Selection.Words(1) 
Set Range2 = ActiveDocument.Range(Start:=20, End:=100) 
If Range1.InStory(Range:=Range2) = True Then 
 Range1.Font.Bold = True 
End If