Breaking change in RC C# compilation

In all versions of the IDE prior to VS8 RC C# build employed interfaces provided by cscomp.dll shipped with .NET framework. Our company uses internal tool that integrates VERY smoothly as preprocessor into the build process by thunking interfaces in cscomp.dll. Compilation options, error reporting and debugging transparency are achieved with minimal coding. Now, it seems, RC has its own copy of compiler in C# package, and while csc based builds still work, IDE does not use cscomp.dll anymore. Any hint on how can we integrate preprocessor into new compilation process would be greatly appreciated. Please, help, whatever you can... < xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />