Would it suit your purpose if you had a command which searched for the next line in the buffer which has a number in it and then showed you just that line?
(defun go-to-next-line-with-number ()
(when (search-forward-regexp "[0-9]" nil 0)
(narrow-to-region (progn (beginning-of-line) (point))
(progn (end-of-line) (point))))))
Assign this command to a key, then go to the beginning of the buffer. Calling this command will go to the first line with a number and show you only this line. When you have done whatever editing you need to do to this line, call it again to go to the next line with a number and so on until you reach the end of the buffer.
If this is close but not precisely what you need, tell me more exactly what would help.