Need help with a tire swing

I know this is probably a simple issue for you folks, but it is a problem
for me.  We are going to put up a rope or tire swing for the kids.  I have
no way of getting into the tree (I have an adult form of muscular dystrophy,
which has caused weakness in my legs).  I can get the rope over the limb
easy enough by using a fishing rod to cast over the limb, tie the fishing
line to the rope, then pulling the rope over the limb.  I plan to wrap the
rope around the limb 2-3 times to protect the tree.  My dilema is that I
need a knot which I can tie at ground level, that will slip upwards to the
tree limb when I pull one of the dangling ropes.  I know this will be a
little tricky as the rope coiled around the limb will have to move for this
to occur.  Hopefully, all will be loose enough for this to occur.

Any help or other ideas would be greatly appreciated.

Thanks,
Jack Rogers