Dynamic packages import at macro-time

[r3d9u11]

Hi. Does Nim supports anything like a "dynamic packges loading"? For example, I 
have 3 packages: 
    
    
    pack0.nim (root package) contains:
      
      var dstBack = 0 # some variable-indetifier (will indicate, from wich 
poackage someProc will be called)
      macro init*(back:int) = # some initialization macros, who sets variables 
value before "someProc" called
        dstBack = back
      value
      macro someProc*(a:int) = # some macros, who will return "someProc" from 
destination package (in choice of "dstBack")
        case: dstBack
        of 0: pack1.someProc
        of 1: pack2.someProc
        else: proc (a:int) = discard
    
    
    
    pack1.nim:
    
    proc someProc*(a:int): int =
      result a += 1
    
    
    
    pack2.nim:
    
    proc someProc*(a:int): int =
      result a -= 1
    

Is it possible to realize this scheme in Nim? Thanks.