yes if the transponder has already been programmed for another car thats it cant be re done, but the remote can be reset and reprogrammed to open/close doors more than once. Id try and get one off ebay and get someone with vagcom who knows how or take it to the dealers to get the transponder coded.
on the key you have if its the remote type it will have your frequency on the side id stick with the same one if its 433 get a 433 key as there isnt alot of information about Leons and if they can accept both.
OK - found it...here's the link ---> CLICKY
just noticed
P/N of the key I have is:
HL0 1J0 959 753 N
thats the one i have and thats 433mhz from a skoda, what year is your car?
its probably cause there all ex cons they employ people just released from jail on probation.
place i took it said they would do it but couldnt gaurantee it, ive known someone who had there keycut by a local shoe shop and they broke it.
what year is your leon is it the facelift one?