DNS Dilemma

I’m trying to set up a DNS entry that points to our web site. Unfortunately our internal zone has been set up as hq01.ourdomainname (ie. hq01.example.com) and if I create an A record for www it has a FQDN of www.hq01.example.com. I need to set up a record that has a FQDN of www.example.com. (ie without the hq01 so that the site appears with the same URL internally as it does externally). I can’t set up example.com as a separate zone as it’s seen as a higher level domain of the existing zone. I hope this makes sense and it may be straightforward but I’m not familiar with setting up DNS and at the moment I’m the only one here to do it.