If you're using Ubuntu, see here: http://ubuntuhandbook.org/index.php/...d-ubuntu-1404/
If not you could turn the wireless card into an ad-hoc device assuming it supports access point mode. If your PC usually uses a wired connection you could then bridge the two connections and connect to the ad-hoc with your phone to have internet access via the PC.
I've never done this personally, my knowledge in this is wholely theoretical but I found this here which defines turning on ad-hoc mode: http://hxr99.blogspot.com/2011/10/ho...-in-linux.html
How to bridge the connections depends on your distribution and the tools you have availalbe. Most of what I'm finding in quick google searches are for using the brctl command. For example, if you're using a Debian based distro there's a bridge-utils package that contains it in the repositories, instructions here: https://packages.debian.org/search?k...s=bridge-utils
(btw, this probably goes without saying, but just in case: if the pc is hooked into the LAN using wireless... just connect the cell phone to the same wireless access point the pc is using.)