v600 Headset ring

Hi,

Does anyone know how I can get my V600's 'twin (wired) headset' to ring
into the earpiece ?

The manual states that an option under Settings/Headset called ringer
options, should allow me to set the ringer to sound through the headset.
But this option is not available on the menu, either with the headset
plugged in or out.

Any help appreciated.

Cheers.