Redirect Url in Hotspot

Hello
I have been trying to do url redirection from dns but it allows only name resolutions of url to ip address, i would like to redirect to a different url for example
when i enter www.yahoo.com it takes me to www.google.com

thank you in advance

What does the Hotspot have to do with it?

Are you trying to do this before or after user login?

after user log on

Any ideas would be appreciated thank you

This can be done in webproxy. If you use webproxy, make new access list rule.
http://wiki.mikrotik.com/wiki/Manual:IP/Proxy#Access_List

in the host enter yahoo.com in the action set deny, and in the redirect-to enter google.com