Examples:
The following VBA example sets a bookmark for each rectangle on the page and links each ellipse to each rectangle.
Sub Test()
Dim s As Shape
Dim col As New Collection
Dim n As Long
For Each s In ActivePage.FindShapes(Type:=cdrRectangleShape)
col.Add s.StaticID
s.URL.BookMark = "Rectangle" & s.StaticID
Next s
n = 1
For Each s In ActivePage.FindShapes(Type:=cdrEllipseShape)
If n > col.Count Then Exit For
s.URL.Address = "Rectangle" & col(n)
s.URL.AltComment = "Link to the rectangle shape"
n = n + 1
Next s
End Sub