Attach rigged character's hands to bicycle handlebars for Unity - how?

Hello Guys,

I would like to ask for some help on this: how to attach the hands of rigged character (like an imported MakeHuman-rigged character) to the handlebar (grips) of a bike in a way that rotating the first wheel would affect the hands/arms of the character. I would like to use the rig/animations in Unity.

I would like to go for the best solution, so please help if you can. Thanks.