not exactly sure what you want, why program in assembler ?
its possible dough but its often slow or developing software, update or remove bugs.
Never the less it is possible.
You might perhaps use a fixed array of char (bytes).
Then read a little bit about pointers in C++ ( http://www.cplusplus.com/doc/tutorial/pointers/
A pointer will get you the offset of where the array is stored
Pointers can point to objects, functions, variables,...
Basically they point to the memory location
next you might take a dive into this http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1207370768/2
I think before you start assembler, first try c++
It might sound cool to be able to do it (i one could write assembler for the MSX), but its not an easy road
It might require lots of time to learn, and you be able to create small things with it, the same investment in other programming languages leads programmes who can do more (but 'might' not be as fast as assembler, on the other hand these program languages do a good job of translating code to assembler too, so you can focus better on higher goals and achieve more with less code to invent yourself.