Denti and Aterpster,
There is a 'Loc' button on the 757 / 767 but it is not Vor/ Loc.
It will track a Localizer
It will NOT track a radial.
You can, of course display any radial you would like and could track it yourself
using Hdg Sel but the Autopilot will not do it for you.
When tracking of a Radial is required you simply build the radial on the legs page and fly it in LNAV.
You can verify you are tracking it if you wish by tuning in the radial manually
which should superimpose it self on the LNAV course (visible on the Map display)