Rigify & Custom Rig

Hi, I'm currently creating a rig which has been created in [B]Blender [/B]with [B]Rigify[/B]. Everything seems to work except that because Rigify doesn't use the same bone chain for "Torso to Head" and "Torso to Hands/Feet", the final Rig doesn't parent the arms/legs to the torso. Meaning that even though I can animate the whole rig, I don't benefit from the stretching propagation (moving the hand doesn't move the torso). I tried to [B]parent the prototype elements[/B] but so far I couldn't find a way to create a "link" (shoulder - spine). Any way to solve this?