change the center point for anisotropic material

Im working on some artwork for a watch I am going to have made and i need some advice on how to make the sub-dial anisotropic material centered on the sub dial and not the whole object.

Thanks in advance!

<a class='attachment' href='/uploads/default/original/4X/1/1/2/112dbf3b35db69608669d78ff1879c81d1b03d17.blend'>dial.blend</a> (1.99 MB)

You can add an empty at the centre of the subdial and then use it as the tangent coordinate

Thanks that worked.