OK. Here is an initial description of a possible foot powered drill. Tie the cordage between two well rooted, flexible bushes - positioning the ropes to attach to branches that bend but springs back, one at least should be attached to a branch coming up from the roots. Place foot with heel against ground and ball of foot on lower part of branch with rope attached. Press with foot to move the branch and the rope should be pulled and bend the other bush too. When you pull you foot back the rope should be pulled back the other way. Then set up your drill, with the rope wrapped round the drill, so you can control the top piece, drill and hearthboard - possibly while reclining, or perhaps sitting and using a longish drill (1-2 feet in length)
Can't wait to try it.