in general — yes. (not sure about Matlab though)
i'd recommend you to install axoloti patcher (it does not require the board to work), create or open a patch, and use „edit object definition“ item of any existing object menu to get an object editing window. when you explore stuff in that window yourself, you very quickly will get how creating/modifying objects works.
i started customizing objects for my needs even without C knowledge very soon, because it's not difficult at all. creating objects works the same way.