http://bugs.winehq.org/show_bug.cgi?id=33513
--- Comment #6 from Hans Leidekker hans@meelstraat.net 2013-05-29 03:05:14 CDT --- (In reply to comment #5)
We have the assembly's strong name: [HKEY_CLASSES_ROOT\CLSID{100D062D-4823-4C3E-BE65-4DA9B82A874B}\InprocServer32\9.0.242.0] Assembly="Microsoft.SqlServer.Setup, Version=9.0.242.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91" The file is located in: GAC_MSIL/Microsoft.SqlServer.Setup/9.0.242.0__89845dcd8080cc91/Microsoft.SqlServer.Setup.dll In general I'm not sure if we can assume that the file name is the same as the assembly name, but in this case this assumption will work.
IAssemblyCache::QueryAssemblyInfo is probably what you're looking for (the one in fusion.dll, not to be confused with the one in sxs.dll).