Hi,

You just happened to catch me working today so I'm actually near the computer!

The link-to function will work with regular 3D geometry like spheres or cubes.

However, with figures, the figure is one big piece of 3D geometry - there is no eye or hand or head. All of the selectors that you see in the properties palette are the named bones that then influence the geometry. So, only in the case of figures, does selecting something like "eye" not work. 

For tight eye lights, I'll usually create a mask and apply it to the spotlight to further shape the lighting.

For pure specular effect on eyes, it's usually better to simply create a custom texture map for the eye using a specific texture for the spec highlight. This can then also be dropped into the glow channel for a sparkle while on shadow sides.