I have power going through a switch, then on to three lights. Want to make one of the lights constant w/o running new wire bypassing switch.

have one set of wires(1 power,1 return,1 neutral) running to last light then other two are branched of of that. As it looks now I would have to cut several holes in wall to fish a new power wire to bypass the switch. is there a way to use a three way or something else to avoid this.Need a constant power source at first junction box after switch. O and cant use neutral . It is bare copper.

diagram would be something like this:

power source-----switch-----1st junction-----2nd junction-----light