Although "nothing" is a noun, it is not a singular term. That is, it does not stand for any element of the domain of quantification. This distinguishes "nothing" from "Aristotle" (which stands for Aristotle). Both are names, but only the latter is a singular term.
Suppose we formalize "Aristotle is here" thus: Ha -- where "H" stands for the property of being here, and "a" stands for Aristotle. Now, since Frege it is widely accepted that the right way to formalize "Nothing is here" is not Hn (where n would be a singular term that stands for nothingness, or some such). The right way to formalize it is: ~ Ex (Hx) -- there is not anything such that it is here (the E should be looking backwards, but oh well).
The idea would be, then, that "is it possible for Nothing to exist in something?" only means the following: could it be that there is something such that nothing exists in it? Which could be formalized thus (introducing the notation Iab for "a is in b"). The question above asks for the possibility of the following state of affairs:
Ex ~ (Ey (Iyx))
I guess that boxes which are forever empty are possible, which means that the answer to your question is yes. There is nothing very deep about nothing possibly being in something.