Networking Question

I'll soon be moving to a place that has a wireless router, but not anywhere close enough to where my computers will be to have a hardwire connection. So, if my blackbook is connected wirelessly, is there any way to share that connection with a PC that will be near it (used for games)? Something like connecting the ethernet ports on the blackbook and the PC with a length of CAT5 cable?

Or will I have to bite the bullet and buy a wireless card/usb dongle for my PC?

Any help would be appreciated.