I have a TeamCity build solution with managed (C#) and unmanaged (C++) projects. Is there a TeamCity utility out there similar to Assembly Info Patcher that will change the version numbers in the .rc files for unmanaged C++ DLL and OCX projects to match the build number?
No, teamcity doesn't have anything to update version of C++ dlls, you could however use StampVer.exe to update the version of C++ dlls. You'll need to download the exe and add a build to call the exe which will update the version of the C++ exe or dll.