Well my friend, you're outside my realm of *cough* expertise. However, I can tell you, that if you're doing partial mashes or even sticking to extract beers you can get a product that is awfully close. For instance if you're going to try a pilsner you can just buy a "Pilsner" or "Extra Light" DME. That'll get you close enough.
The problem with copying a water profile is that you have to copy the water profile. There's no "kinda copying". You have to just do it. So here's my two cents....
If I were you, and in search of a very authentic style (Pilzen, Burton, Dublin, London, etc.) I would do a search for the water profile of the region, then one of my own (always have this handy), then use any number of charts to figure out the salt additions to mimic that region's water supply in an all-grain. Like I said before, this is well outside my range but I think in the truest sense, yes the DME is going to alter the flavor to the very dedicated taster enough that they could point out something's off, but for the rest of us, it'll taste like a delicious lager. If you really want to be legit, go all out.