Why do you need to go to a specific page number? If you want to go back to where you were, add a bookmark; do you need to go to a specific unvisited location, use the table of contents or search in the book itself. If the epub itself is referencing a page number to go to it will probably be a clickable hyperlink.
In regards to your analogy, it seems like you're asking where the hand crank is on your car.
