Problems switching FK/IK

Hi all.

Im working on 3dsmax 2009 making a control rig for a humanoid. I have all done, but i have a small (or big…) problem trying to switch the FK/IK in the leg system.

Should be a typical problem, but this is one of my first riggings: When i acced to the IK Chain object i can disable the IK, but then the foot unlink to the leg. And i cannot parent the foot control to the IK for obviously reasons…

Anybody here can get me a hand, please?

Pleased to meet you!

Thanks!

PD: Appologize for my english, i know that is not the best…