I hope this has not already been talked about but i have worked out how to use this script as a tunneler. Its not the script that needs setting up but the ship itself :)

Make your ship as normal but with one change Do Not Connect the cargo connainer to the drills.
The ship must have a cargo container and it must have enough space to hold more than the drills can hold.
if you find it still doesn't work after modding a ship use the Reset command and recompile the script.

I don't think i missed anything, Let me know if it worked for you :)