You can specify a single file in your project to be a precompiled header by setting the project option Precompiled Header File on the file node of the project. The file should be project local i.e. in the same directory as the project file and should include the header files that you wish to be compiled.
You must set the project level option Enable Precompiled Header File which supplies the output file generated by the precompiled header file to the compilation of each file in the project.