Tether wireless connection to ethernet port

I have an iMac 7,1 running version 10.6.4, I have it wirelessly connected to the internet using an airport express. I also have an older windows desktop without a wireless card but it does have an ethernet card. Is it possible to somehow tether my iMacs wireless connection though my ethernet port on my iMac and feed it to my windows tower. The simple solution would be to hard wire it to the modem but it's just to far, and if I can get around spending money on a dongle or wireless card it would be a plus. I believe I'm average as far as my ability to navigate through both systems but I can't seem to figure this one out.

Any help would be greatly appreciated.

You could probably do that but it's not really a good solution. What you're suggesting is an internet connection sharing setup between the iMac and the Win machine. Believe me, it'll wind up being slow. You'll be better off buying an inexpensive wireless USB adapter for the Win machine. They're plentiful and inexpensive. Most are plug and play for Windows. You'll be up and running in no time.