you mean like a lattice? you can put things in a lattice by going to (animation) deform>create lattice

or you could group the objects together?

or better yet, oh, wait, sorry just thought of a better way (well, i think this is more what ur looking for)
if you're tryin to create an object which you move and will control the movement of an object (like a foot) thats easy
for sumthing like a foot (for example) take the IK handles' selection handle (go into component mode to get to this) and move it out in front of the foot so you can grab it easily
thats one way, another way:
open up your connection editor, create a cube and put it somewhere so u can easily select it, connect up the IK handles' attributes to the cubes attributes so when you move the cube, you move the handle
or another way: etc etc
as you may have noticed there are a quite a few ways to do this or I could be completely wrong and i wud have typed all that out for no reason! lol which i dnt mind cos im in a friendly helping kinda mood atm
at least i know you dont need a mel script for it