Looking through the different packages, it does not look like this is an option with the free option.
If I have to pay, it looks like it's just a matter of dollars between the two.
But it's good to have some positive feed-back.
Looks like even with the "Enhanced" package at $15, you'd have to use one of their domain names:
No-IP Enhanced is a great choice for users that individuals and small business that want to run their own website or blog, access their computer or security camera remotely, but have no need for their own domain name.