That's it. Vectors are still matrices after all. To me it was natural write V(i) instead of V(0,i) , but I got it now. Maybe this can be a suggestion for future updates, just to clean up some notation. Thanks for the help!
Not sure if you know that you don't need to fill the place holders for the sum if you want to sum up all elements. This will work for a column- and a row-vector alike.
If you really just want to sum a specific range of elements I would prefer the method Terry had already shown. Just for fun here are a few more you could use as well