It can definitely be done. I did this myself to my wife's car with the use of a VAG-COM tool. Visit ross-tech.com for more info on that device.
Anyhow, there is a place that you can change the cars response to a lock or unlock. You have the option to have it blink the lights and honk the horn, or just do one, the other, or neither. This goes for both lock and unlock.
In the case of my wife's car, we have it never honk, and just blink the lights, for both lock and unlock. This feature of turning this on/off works for the Eos, the new Passat, the Mk5 VW... and frankly most recently cars too like the B6 Passat, the Mk4 VW, etc. Its been a function available for some time.
As for how to get to this function -- its in the long coding for the Mk5 and you can refer to THIS thead for more info, and a PDF for coding. Cheers!