Exim forward to another host when user is not in current host

Hi there

i have a unique situation where I have an exim mailserver running in cPanel. we run the the mail server in a separate server and use cpanel for web hosting only. The same domain is used in cpanel (Web) as well as our mail server (Email). Hence when someone submits a email form (contact us), it tries to send the mail to a local host because it thinks the domain is local. We need to it send it to a separate host. Does anyone have any idea on how we can make this work?

I have seen mail servers where it provides an option to forward to a separate host if user was not found in local server. Does exim has such option?

Many thanks in advance.