Assigning Hostname to a Virtual Ip.

when i key hostname it gives me the principal ip which 163.xx.xxx.xx

but i have got a virtual ip which is
163.xx.xxx.yy

can i assign 163.xx.xxx.yy as my hostname
coz i am having my webserver which is referring to principal ip ie hostname .

I want to make my webserver weblogic to listen to virtual ip.