Hi Dounin, thanks for the link
I have actually read it more than once before but it helps when someone puts it in context for you!

So in other words my first location;
location ~* \.(jpg|jpeg|gif|css|png|ico|js)$ {
expires 7d;
}

It will serve all files with that file extension and then no other matches or locations will be used, I've got that right?
In that case I guess we will have a little difficulty implementing the expires directive for our site
Is there some other way we could implement it and still do the rewrites?