howto prepare cpanel account for migration

Hi

Let me explain in detail what my objectives are. I have one ecommerce application that is hosted on domain X and I have new ecommerce application ready that is going to replace that older application that currently occupies domain X. The new application however is not quite ready to launch but I do need to test it on domain F.

In order to test the application on domain F I need to create a Cpanel account (by the way I am not sure if I should refer to Cpanel or cPanel) which by itself is no effort but at the same time if all I want to do is point domain X to the current IP of the new application can't I just change the IP in the DNS that is done at the registrar and be okay with that ? Or is better to just install the new ecommerce application on a account that bears the name of domain X of the old but current live application ?

What is Wisdom in this case ?

Regards