Hello I have a two locations quest , since it follows another quest that shares one location , it happens that when the second quest starts some actors may still be in previous quest location ... how can I do to move ( at a certain player action taken ) all the actors involved to their original basic positions in the "shared" location?

I am not sure what exactly you mean, but maybe you want to take a look at http://www.creationkit.com/MoveToMyEditorLocation_-_ObjectReference.

thanks I will try ...

Seems is not working ...

I am using this function in a fragment script stage

Starting 1 compile threads for 1 files...
Compiling "QF_ISSGARDJourney01_0107303D"...
e:\giochi\steam\steamapps\common\skyrim\Data\Scripts\Source\temp\QF_ISSGARDJourney01_0107303D.psc(82,13): MoveToMyEditorLocation is not a function or does not exist
No output generated for QF_ISSGARDJourney01_0107303D, compilation failed.

Batch compile of 1 files finished. 0 succeeded, 1 failed.
Failed on QF_ISSGARDJourney01_0107303D

You probably didn't use it correctly. It should be used like this:

MyObjRefOrActorProperty.MoveToMyEditorLocation()

wait I did as MYACTORNAME..MoveToMyEditorLocation()

wasn't that correct?