Don't follow the question, precisely? Of course you can associate any element of any array with a temporary variable as you've outlined, but why not just use the reference directly?
Answering my own (admittedly somewhat rhetorical) question, there is one reason in that it's less typing to use the single-character variable names or there may be a physical interpretation of the elements such that it's convenient for documentation purposes of reading the code. But, it's immaterial as far as Matlab is concerned.
So, again, what's the real issue behind the question?
