Inbound Faxes to a pool of Fax Extensions

I have set up a pool of 3 IAXModems connected to Hylafax to accept inbound Faxes. Does anyone know how I can set FreePBX to use whatever Fax Extension is not currently busy?

I have tried setting up the first Fax extension with Follow me to each of the other extensions, but the Fax detection script seems to bypass this. It does not appear to be possible to set the Fax Extension to be a group.