Yes, it's possible in VS2010, but there's no UI for creating the subset. Instead, you'll either need to either specify the inclusion/exclusion list via the CodeAnalysisAdditionalOptions MSBuild property (using the /types command line parameter that
will be used when running FxCopCmd.exe) or via a .fxcop project file specified via the CodeAnalysisProject MSBuild property.
The latter approach caused problems in VS2008 since FxCop would attempt to load the target DLL twice if it was included in the project file. I haven't tried it in VS2010, but it's certainly worth giving it a shot before resorting to the CodeAnalysisAdditionalOptions