I mickael,

It would be possible to have a "booleen track" fonction, to create a "track" (boolean) of an object selected in the base object without to have to :copy the object selected , hide the original to just keep the copy , and after make the boolean in the base object with the object duplicated.and after unhide the original object...

It will be more efficient to selected the base object, choose the boolean track fonction , and selected the whished object and voila !
the base object has the track of the object, and the original object is still here with no cut and no boolean in his shape.It will be good that this boolean fonction create a light gap, to don't have any intersection of surface beetween base object and wished object.

Sorry for my poor english, it was difficult for me too explain what I want but I hope you understand me.

Thanks

Alex