Using putty for an X session

[adam.edgar]

Unfortunately at work I must use a windows machine, but Id like to be able
to use Putty to connect to my machine. I can bring up a standard SSH2
session but I am ignorant when it come to starting an X session remotely.
How do I go about getting X on my machine at work? I know it has to do
with starting X on a new display. Should I use startx -display ?????? and
if so what is that display.
Thanks
Adam Edgar