F5 Edge client DNS host file edit

We have a Mac client who needs to query our internal DNS server to an external server. However, we use split tunneling which prevents the client to do the internal DNS lookup. So we tried to edit the local host file on the Mac to resolve the IP address but found that when the Edge client connects, it ignores the local host file and uses it's own host file. How do I edit the Edge client host file to add the IP/URL so the local client can resolve the IP?