Website Redirect help

My boss asked me to do this:

“I would like if someone types in: http://www.plateaupediatrics.com/register

that it will redirect automatically to http://www.plateaupediatrics.com/wp-login.php?action=register

If you Google “URL website redirect” or something, you should be able to read how to do this (simple scripting)”

I have tried to install some plugins to accomplish this task and they don’t work. The one I have activated now is Simple 301 Redirects. I think my problem is that http://www.plateaupediatrics.com/register doesn’t exist. I tried to create that website, but I couldn’t customize the permalink to make it correct. I have also searched google extensively, but I don’t understand a lot of the instructions.

Can anyone help me? I’m not very tech savvy and my “WordPress for Dummies” book doesn’t explain how to do this.