I need to connect to the company VPN. The official way to do this is using Netscreen Remote, which as far as I can tell is Windows-only. Is it possible to get connected using Snow Leopard's built-in VPN manager?
use VPN Tracker
Here the document which explain about how to configure and access net-screen on mac
I would say of course you can use the built-in client ! It should work like any other client.
For me it works perfectly, even if my University tells me to use its own client.
I think the built-in client is a complete client.