See if there are spaces in the path to CApp.o. If there are, configure your environment to add quotes around paths. You may also want to force it to use forward slashes rather than backslashes.
I believe that you have to put your include definition in quotes instead of brackets because it is not part of the standard library.
Boy, you suck.
Quotes in includes are used when the file you want to include can be found in a path relative to the file that does the inclusion. <> are used to make the compiler search for the file in its inclusion directories.
And how I do it, helios (I'm using CodeBlocks and Windows XP)?