Hiya..
I think I know the pipe you're talking about. Is it the hard plastic one that comes off the "Y" shaped rubber pipe that comes off the rocker.
If it is the VW part number you need is 06A103213BG. This is the pipe I had to buy from VW as I was in hurry at the time & expect to pay around 40 quid

I think VW said it was the lower oil breather pipe.
I'm sure you can get an uprated pipe off e-bay though but I have no link for that sorry.
Anyway hope this was a little help.