ROD stretch handle using multipartpath

Hello,
I want to make an instance ROD () from a strechable multi-part path. I cannot figure out in the documentation how to do it.

Does someone have a template exemple from A to Z on how to do so ?
Something like :

CREATEINSTANCE("myLibrary" "myCellView" "layout"
...
leDefineMPPTemplate(
               ?techId            tech
                ?name             "template1"
                ?layer             list("MET1" "drawing")
                ?width             0.600000
...
?offsetSubPath  
    ...
 ?subRect  
...
)

Thank you in advance form any kind nice method.
Please note that i want graphical strech handles on the instance.
Thank you so much.
Regards,