Not too sure about re-coding keyfobs yourself; when acquired my A4 had 3 flip-keys but 1 of them wouldn't 'talk' to the immobiliser so ended up paying a main-stealer to re-code it to the car.....cost was about £40.
You need to find a VW dealer that cuts the flip-type keys.....
I purchased via Ebay a key blank (as a spare) but not a single local key-cutting place would even attempt to cut it, saying they were a nightmare to cut properly.....
Undaunted I tried at my local Audi Centre parts dept who reckoned that they had to send away for them as they are laser cut at a cost of approx £35 /ubbthreads/images/graemlins/shocked.gif .......(something that I later out found was garbage /ubbthreads/images/graemlins/grin.gif ).
Eventually I discovered that a large VW dealer about 30 mins away was able to supply and cut the keys whilst I waited,their charge was £5.32 (inc vat) for the blade supplied and cut; they even cut my Ebay blank for free too!
/ubbthreads/images/graemlins/wink.gif