We are not in your head nor do we have the C (or Basic?) source code in front of us. So if you throw some code line at us without any context it'll be hard for us to help you. Also note that the intersection of Nim and Basic developers is probably very small (as opposed to Nim and C) so asking questions along the line "In Basic it's done like that. How in Nim?" will risk to severely limit the set of people willing and capable to help you.
As for your question 2: Nim knows that `proc` is obviously about an address.
