Been a while since I've done Lisp seriously, but I don't believe that's possible, at least in Common Lisp (SBCL). While if responds to symbol function:

  * (symbol-function 'if)
  #<CLOSURE (:SPECIAL IF) {1000C5084B}>

SBCL refuses to set that value to an alias:

  * (setf (symbol-function 'foo) (symbol-function 'if))
  #<THREAD "main thread" RUNNING {10005205B3}>:
    #<CLOSURE (:SPECIAL IF) {1000C5084B}> is not acceptable to (SETF SYMBOL-FUNCTION)

Trying this with regular functions works as intended:

  * (setf (symbol-function 'bar) (symbol-function 'mapcar))
  #<FUNCTION MAPCAR>
  * (bar #'1+ '(1 2 3))
  (2 3 4)

Special forms are, well, special and a lot of the regular parts of lisp doesn't work with them.