I think in this case you'll have to go to the dealership and order a key. Many VW dealerships don't have the ability to cut a key from factory code (lazer cut type), so they will order a key from the VIN (vehicle identification number) that the facing parts depot can cut.
It won't be inexpensive; the least expensive key a sub master (no keyless entry remote, but will open the trunk and glove box) is about $50 or so and that doesn't include the cost of programming the key to the vehicle. The key in extreme cases can be ordered overnight if need be, depending upon how close you are to the facing parts depot. In some cases, an additional charge for expediated handling will apply to get the key as quickly as possible.
Once the dealership receives the key from the parts depot, most of them can cut a duplicate key of various sorts (i.e., remote type, valet (opens drivers door and starts car only) or another sub master key that doesn't have a remote built in to it.) Please note, the key(s) will need to be programmed to the vehicle before the car will start.....
My suggestion is that you cut at least one or two keys more; it never hurts to have a spare key available to avoid the situation you're currently in. Also, you can save money by programming however many keys you want, if you do it at the same time... most places have a fixed labour charge to programme keys to vehicle, regardless of how many keys are being done, as long as they are all done at the same time. Normally, the labour charge runs between .75 hour to 1.5 to programme keys, around where I'm at in California, most places charge 1.0 hours of labour at the posted hourly rate.
Hope this helps, a car nut.