What you are asking is how to model a simple four-bar linkage (the ground is considered one of the 4 links) that uses a set of 4 pivots. Four-bar linkages may also include sliding joints.
For your example just add a dummy object at the pivot point of the pink object and link it to the pink object. Then link the IK chain to the dummy object.
I put the following tutorial together to show how to model a 6-bar linkage with 3ds Max. You may find it helpful. I used bones but it is not necessary. You can use simple object linking between objects instead of bones.
https://www.youtube.com/watch?v=cm7OP3niwvI
~Lee
lee.minardi
