Compile single file

[pjaquiery]

Set your project up to use a custom build step that does the .IDL compile then fixes up the headers.

Generally it is much easier to get everything working if you can use VBP to build your project in the same way that it is built from the IDE, so using configurations to provide settings rather than futzing with the project files and using a custom tool rather than a "manual" edit step are likely to get you there quicker.