Achieving dynamic pass for lightmapped objects

For long time I thought it was impossible. Took me several months to find the way. Indeed, its already implemented, so I didn't have to do anything by myself.
For now, the method I've found consists in a few easy steps.

1. Set lightmap mode to Dual and check "Use in forwar render"

2. Add dualforward directive: #pragma surface surf TriAce dualforward
3. In case you want to make something different when using lighmaps, this is available:

        #ifdef LIGHTMAP_OFF
final.rgb= BRDF*Light;
#else
        final.rgb=whatever;
        #endif

And as extra, a Beast setup file that looks fantastic and does the job very fast.