no pd doesn't do something like that. abstractions need to be available as separate files to be reusable. however, i remember miller has mentioned that he plans to allow (reusable) abstractions inside the main-patch. however, this has been a year ago, and it seems to not have made any progress.
(but probably he has just forgotten it, so your mail might remind him and it could get implemented for 0.40 :-))
(Miller? .... hello Miller?)
Personally, I would find this very useful ...(maybe I am alone)..
because often, one has to create external *.pd files which will only
ever get used inside the 1 main patch.... this means:
minor.. but it _has_ happened to me)
Etienne