Peated malt and smoked malt are not the same so don't confuse the two. Since you posted this in extract forum I'm going to guess you don't mash at all and don't want to at this point. If that is the case, then peated malt is what you want to use, but you only use a LITTLE bit or it will taste like burnt plastic. A good start will be to steep 2-4oz for a 5 gallon batch. Steep either with the other specialty grains you will be using with 1-2 gallons of water at about 150-160degrees for 30 minutes. As others stated above, rauchmalt needs to be mashed to prevent a very starchy and thick beer to still get the amount of smokiness you are looking for. Liquid smoke is a definite no-no unless you are playing a prank on someone.