Share macbook WIFI on wired LAN

Is it possible to share internet connection from my Macbook to my desktop (wired of course)


I got a stubborn landlord who doesn't want to let me use LAN (wired connection) because he's to cheap tp buy the cat5 cable :S

I onlu got internet connectons via wifi on my macbook.

Heres what i want to do:

1. Connect via wifi on macbook to my internet
2. share the wifi connection from my macbook to the macbook LAN port
3. run a cable (not sure if I need a cross over or straight from macbook to desktop LAN port
4. use internet on desktop freely as if it was connected to a normal LAN cable

Notes:
Mac OSX 10.5.8
Desktop PC is a Windows 7
I use Little Snitch on mac and Zone Alarm on win 7
I guess i need to do configure firewall settings on both machines

If I were you, I'd just buy a USB wifi receiver for the PC. No hassle. No wires. No need to turn on both computers just to use the PC.