Do I HAVE to dial 9 for fax clients?

We've got an elastix server that receives faxes for us. In order to ease the migration I continued to allow the users to send faxes via old school fax machine. Now that we have faxes coming in successfully we want to get the few that need to still send faxes setup to fax from their desktop. I've successfully tested this using Winprint (if there is a better FREE windows fax client please let me know), however, I have to place a 9 in front of the number to be dialed. Obviously, I wasn't surprised by this but was hoping that there was a way to have elastix grab dial tone without the users having to place the 9 in there since they are faxing from an address book typically. Not sure if this is even possible but thought I would ask. It may be as simple as modifying the dial pattern, but I don't want to affect all extensions just those that...