There are a number of companies that supply the equipment needed for this type of job. Arcair (div. of Thermadyne) sells the Arcair Slice Pack. There are a couple of ways to use this equipment. basically it is a pistol grip with an air line and collet. the rods are exothermic coated steel rods that when ignited and supplied with oxygen through the middle, produces the heat required to melt steel, and the oxygen pressure is there to not only enhance the flame, but remove the molten metal. You can use the unit with or without a welding power source. the rod is ignited and the oxygen is supplied with the handle depressed. the rod can be ignited with a torch, or the electrical sparks of a standard car battery with the proper "striker" that is supplied with the kit, or the unit can be hooked up to a cc power source and ignited with a scratch start, much like starting a welding rod. the rods come in 22" and 44" lengths at 1/4" dia. and for larger diameters (3/8"+) they are 18" and 36" in length.
You will definitely need to wear some leathers (head to toe would be good) since the molten metal will be spraying everywhere. (the oxygen pressure should be about 80 p.s.i.) once you start the pierce, you will need to manipulate the rod in small circles to penetrate and remove material, at the same time as inserting the rod into the cavity that is being created. Usually you don't need to remove the pine entirely, as the heat generated will usually cause it to break free from the surface. some persuasion with a hammer will usually remove it after the hole is pierced all the way through. Keep in mind that this process is pretty much the same as carbon arc gouging (noise, smoke, spatter, etc.)
For larger pins or demolition work, burning bars up to ten or twelve feet can be used, pretty much the same process, only on a larger scale. (check out www.canadianpipesupply.com for and example of the types of bars and holders are avail.)
sorry about the length of the post, just got typing and forgot to stop.