forward an internal private ip to external

I want to do things backward apparently.

we just installed a new XG12

I need to forward tcp requests from a phone app called Fonality Hub from my internal computer network which is on an XG Firewall 192.168.1.X to my internal phone network Fonality server 10.100.10.5

Is there any way to setup a rule to route traffic destined for 10.100.10.5 to the external ip of the fonality server?

thanks

Greg