Any way to do this with a minimum of queries?

I log IP addresses on my site, along with the persons username. Right now, they are logged in a seperate table, but I would like to store them in my users table now. I can't start my ip logging again, since the list of ips is also used for a hit counter. What is a good way (if there is one) to transfer those ips with a minimum of queries? I use a mysql database. Thanks!