Silly machine based translation!
What we encourage is keeping the .x10.mx as a backup in case there is trouble with the domain (in your case, homsi.com.ar).
Add it to your account as a Parked Domain, and it will show the same site as virtualdelivery.x10.mx (note that it doesn't forward to the other site, it actually shows the content...if that makes sense).
With regards to changing what your site uses...that's something you'll have to look through the configuration files for as it's a 3rd party script, I'm afraid. If you get stuck by all means ask here but it's like asking a Microsoft dev a question about an iPod. Hopefully it's just one configuration entry!
I'm going to close this thread - please feel free to reopen it or create a new thread if you need more assistance.