301 redirect problem

We have 2 domain names that are just 2 different ways of spelling our company name. I was using the standard forwarding that comes with 1and1.com to forward the one url to our main but then noticed google indexed the one I was forwarding which I assume is not a good thing and will end up being duplicate content in the long run. We do not have hosting threw 1and1 just the 2 domains. I point my main url to my ecommerce stores name servers. I contacted 1and1 and they say there is no way for me to create a 301 redirect. How would you suggest I go about this?