Situation:
In a multi site system using domain mappings the possibility of regular

The RegexpVirtualURIMapping implementation is not very applicable, as no selector in the URL can be used for applying the pattern only for a certain site. The handle prefix is mapped away by the domain.
Therefore the pattern would apply to all sites with the same paths detected.

The possibility of using a HostBasedVirtualURIMapping solves the problem of reacting to the mapped domain as selector. But the HostBasedVirtualURIMapping is not regex capable. So fort redirecting the parameters as described in this support ticket SUPPORT-3223 is not a usable solution.

A new kind of VirtualURIMApping which is either hostbased & regex capable or uses some other sort of site definition mapping/selector would help in many multi site situations.