Am I right in thinking your brother is the keeper of the vehicle, and so VCS are suing him - but you were driving on the day? In your first post you wrote "I received a PCN" but did you really mean your brother did?
if so, you can prepare the paperwork in his name if you want, and a decent defence later on will probably lead Simple Simon of VCS to wet himself and give in (if you look through the forum, there are very recent examples of this).
However, in the unlikely event that VCS go all the way to court, it will be your brother appearing, so it'd be a good idea if he too started to learn the legal procedure and how to beat these fleecers.
plenty of our two - five line generic defences here already
but you are far too early yet to bother about defence.
your job now is to get reading up any/all PCN claimform threads here in this very same forum
get upto speed.