I don't think that's how the hotspot works on cell phones. What they do is turn their data connection into a wifi shared connection. I don't think you can take a wifi connection from another source and turn the phone into a wifi router.
Did you check the manual on this setup? Can you use that phone to share an outside connection or only the one that the phone has?
If you just want to share out the computer's connection you can do that with a wireless card and turning on Internet Connection Sharing. But you'd be better off getting a Router and using that.
I have a Samsung Galaxy S2 and I can use tethering on it to share a wifi signal with multiple computers. However, this is not what you are asking for. Phone tethering converts the 3G phone internet connection into a wifi signal that computers can connect to so they can access the internet. I have not heard of what you are looking for -- using a phone to send an internet connection from one computer to another. As hang-the-9 says, I think you'll need a proper router. Let us know if you find out otherwise.
Get a router, and connect the phones through that WiFi. No need to mess with all sorts of connections. What you are trying to do is maybe use ICS to share out the PCs internet, then you can use the phone's wifi connection to connect to the PC. For that, you need to get a wireless card for the computer, then you can connect the phones to it. But a Router is much simpler to work with.