Single press unlock?

Im sure this is possible i think i had it done on my old mk4 golf, but cant for the life of me remember how it was done! Doh!
 
My local dealer said it couldn't be done but it seems I was right to doubt them. So can independent specialists do it or can I pick up the kit to do it for sensible money?
 
Vcds I have done it, can't remember the code and I'm not home to look I'm sure someone will have it to hand.
 
I did this on my S3, dead easy.

Info from ross-tech site..
Central Convenience Controller Coding:
State Bit Dec. Function
OFF 0 1 Great Britain- alarm system (only with bit 4)
OFF 1 2 flash on when arming/unarming alarm system
ON 2 4 selective locking 1 door/all doors
ON 3 8 activate alarm system
OFF 4 16 rear unlocking block via speed
OFF 5 32 locking via speed
OFF 6 64 comfort functions with remote (adapt in ch 62!!)
OFF 7 128 right side steering
OFF 8 256 avant (glass break sensors in rear side-and rear
windows (if error: safe-LED constantly lit ))
ON 9 512 1x flash when lock with remote
ON 10 1024 horn sounds when lock with remote
ON 11 2048 door/window-logic ( ignition off: No open door
el. windows works 10 min )
OFF 12 4096 normal/????-alarm system
ON 13 8192 No SAFE-function USA only
OFF 14 16384 insulate-glass PR-nr 4KR/4KV

Again, we can verify that we did this correctly by adding up all the decimal values for the bits that are ON:

4 + 8 + 512 + 1024 + 2048 + 8192 = 11788.

Now notice that bit 6 with a value of 64 and function "comfort functions with remote (adapt in ch 62!!)" is OFF !!! So in order to turn this ON, we need to add 64 to the original coding. 11788 + 64 = 11852. Recode the module with that number. Once you do that, the options in Adaptation Channel 62 should take effect, and you can change the value there to "fine tune" the features..

If you wanted to add "locking via speed" (where the car locks itself as soon as you reach some low speed), you would add 32.

If you wanted to turn Selective Locking OFF, (so the entire car unlocks with one press of the unlock button on the remote) you would subtract 4.