Ahh, now I get you.
There are a couple of options:
1) Your first zp does not have to be connected directly to your computer, it can do so through a router. So you could have pc in one room, router in another (or the same room), and first ZP in another. Ideally, you want your sonos connected to your BB as well so you can stream internet radio etc, so the router scenario is the best. You can run a cat5 cable from your pc room to your first zp anyway.
2) You can locate your ZP on top of your PC, and just run your speaker wire from there to the room your putting your speakers in.
3) You do not need to have all your music stored on a pc, you can store it on a nas instead.The NAS could be put next to your first ZP, but either way the ideal scenario is to have everything connected through a router.
4) There is a way to use a wireless bridge between you first sonos and your pc/network. If you look at the forums on the sonos website you will find it, although sonos do not "support" that set up.
Regards,
Eamon