Is it 5 or 6 speed?
If it's the 6 speed, then you'll need the Lupo GTi specific shafts, if it's the 5 speed then I THINK the Polo GTi ones will work.
I bought some off ebay recently from a guy breaking a 6 speed to keep in the garage in case I ever need them, then I don't have the stress of trying to source some.
There are also some new ones listed on eBay, but check carefully as a lot of the part numbers listed with these aren't for the 6 speed versions.