Process a list (and any sub-lists), expanding certain symbols.
Symbol Expands To
N (match-string N) (where N is a string of digits)
#N (string-to-number (match-string N))
& (match-string 0)
#& (string-to-number (match-string 0))
Note that these symbols must be preceded by a backslash in order to type them using Lisp syntax.