So sorry, I didn't see your post until now. For an extract recipe, you could use 7# Light DME and use the same amount of Munich, Special B and Carapils as steeping grains. Unfortunately, there isn't a Vienna extract, so you'll just have to use light DME. Or, you could reduce the light DME and do a mini mash that includes the Vienna.
h-bar Brewing: A Random Walk of Beer Styles