SMIL 3 Linking

Hello Sir or Madam,

right now I am trying to figure out the Linking Module of your 
comprehensive language. My main focus lays on using fragments of 
existing SMIL presentations to create mashups.
I used the Ambulant Player to have a go at SMIL and Linking, but I am 
not quite shure if it is behaving as intended.

The w3c documentation ( 
http://www.w3.org/TR/SMIL/smil-extended-linking.html 9.5) says "/Links 
using fragment identifiers enable authors to encode links to a SMIL 3.0 
presentation at the start time of a particular element rather than at 
the beginning of its presentation./"
The question is wheather this means you can use fragment identifiers to 
define the referenced fragment by time only and you always get the whole 
refereced smile file / presentation at the given interval.
For example if you have a presentation consisting of a menu and a 
display region for media, both persisting the whole time. Is it possible 
to reference and use the menu in a mashup without including the display 
region?

Hope it is clear what i am asking.

Thanks in advance
Heiko Scholz