Redirect based on country of origin?

I run a few proxy sites and I was wondering if I can add a script to redirect users from specific countries to another proxy with different ads showing.. or display different adds to those users only?? Is there something like this available? or would it be easy to code?

thanks

 

yes this is easy to code

and if you serch over google you will find many script for this

 

google .com , use u search , or you can config apache host