Nonalcoholic Substitute for Marsala Wine

For personal reasons I won't purchase alcohol or have it in my home, but I'm a bit of a foodie and love Chicken and Steak Marsala. I've found decent nonalcoholic substitutes for dry and sweet white wines and burgundy (Meiers Sparkling Juice), which covers most of the recipes I've wanted to make, but I've never found a good substitute for Marsala. Are there any non-alcoholic versions that would pass in a recipe, or a decent mix of other juices or ingredients that would pass, even if I have to process it somehow?