Specify a preSolution global section in Visual Studio.
Setting a property like this generates an entry of the following form in the solution file:
GlobalSection(<section>) = preSolution <contents based on property value> EndGlobalSection
The property must be set to a semicolon-separated list of key=value pairs. Each such pair will be transformed into an entry in the solution global section. Whitespace around key and value is ignored. List elements which do not contain an equal sign are skipped.
This property only works for Visual Studio 7 and above; it is ignored on other generators. The property only applies when set on a directory whose CMakeLists.txt contains a project() command.