If you want to use an exisitng domain of yours as part of your Iracks.com order rather than register a new one you simply need to select transfer on the domain page when placing your order and enter your domain. Then process your order as normal and once you have received your confirmation email you can point your nameservers to YourHosting. The details of the nameservers will be provided on the welcome email of Iracks.com while you signup.
For further information on transferring from different hosts or if you need any help regarding the transfer please contact us at [email protected]