MATLAB is not really designed to carry units with variables. (Dimensions, if you want to call it that. I'd suggests units is a better word here, because dimension also carries a different meaning with respect to arrays. Of course, the word units also carries various connotations. Oh well.)
Yes, you can do what you want, with things like the symbolic toolbox. Or I do recall seeing a toolbox designed specifically for units purposes. To be honest, they will just make your code slower, MUCH, MUCH, MUCH slower. At some point in time, that would be important to you.
In the end, I'll argue you will come out ahead in MATLAB by learning to write code that does not rely on the crutch of units. I know that it is nice at first.
