Mapping Colour to Lineweight for Linked Files.

[gj]

We have a lot of legacy Autocad files which we would like to link to a Revit model. Lineweights seem to be the main issue. The Autocad files have naturally been drawn so that colour will be mapped to weight via a *.ctb file. So far I have only been able to find layer mapping to weight in Revit which is unsuitable as elements on the same layer commonly have different weights.
Is there a function for mapping colour to weight in Revit ?
What is the most efficient practice for drawing in Autocad files and linking to Revit to circumvent lineweight issues ?

Mod Edit: Subject changed to reflect content.

[beegee]

I think only mapping by layer is available.