Yes, this is possible. I have done it.
Create a rule in your URL Filter. Make it like this:
URL.Host equals www.request.com
Action = Redirect
Add a new redirect rule, pick User.defined URL, and then add you the site you want to send them to.
I do not see anything where I can make such a policy. We are using Webwasher 6.8.7
The possible options I have are:
Allow on weekends
Block during work hours
Time and Vol Quota
Thanks for your help. I have located the custom actions under the Configuration Tab. This works perfectly!