Php, DNS question

Ok, this is about as clear as mud to me so I’ll do my best to make the question sound intelligent. The company I just created a flash page for has a mail form that, when you click the Submit button does
loadVariablesNum(“contact.php”, 0, POST). Now, everything works fine when I submit the form from my site because I changed the DNS information. My domain name is registered with register.com and my Web host is iPowerweb.com. So my DNS info is something like ns1.ipowerdns.com.

The company, however, refuses to change their name server info to their Web hosting company because they say they won’t have as much control. So the form doesn’t work because something isn’t routed properly. Anyone have any suggestions?