Bill,
From what I have learned, it is easier to fix a small mistake rather that a large one. Once you decide on the best route to take so you can gain access to your destination, drill a 3/32" hole into the cabinet wall or partition. If you hit steel try another location 1" away. If all is good. drill a 1/4" hole thru the 3/32 hole. Take a coat hanger and probe the 1/4" hole for access and obstacles. Once you get that far, drill the size you need to pull all cables required. Fun project and rewarding, Hope this helps, Fred