yes, you create ik handles to the end of the leg - they need not go all the way to root. and then you parent the handle to a locator or other dummy object. set a key for the dummy object. and if you move the root the foot will stay in place. of course if you pull too hard, the foot will move - it is on a "rubber" string connected to ik handle.
hope that gets you started. you need make you own mistakes to master it
p.s.: the key setting is not needed - but in animation you might want to set a key once the foot moved in place. and set a key again before it shall be moved away. but i think you know more about animation than i do :p