These viruses don't work like that Sticks. They use a fake 'From:' address to hide where they come from - and who's computer is infected.
The virus selects this e-mail address from the address book of the infected computer so this address is not the one of the computer with the virus.
If you look at the e-mail headers you can sometimes tell the service provider of the person who's computer has the virus though.
You can do a free online virus scan at
http://housecall.trendmicro.com/