>In the Main.prg of the project I'm working on, I get the error "variable 'varname' not found" on the line APP_GLOBAL = NEWOBJECT(APP_CLASSNAME, APP_CLASSLIB). I looked in my project classes and sure enough, APP_CLASSLIB does not exist. Is there any way to find APP_CLASSLIB and replace it?

APP_CLASSNAME isn't a literal cause it doesn't have quotes or brackets around it, its either a variable, or (for some reason to me it looks more like a) compile time constant.

Look in any .h files for something like: #DEFINE APP_CLASSNAME MyApp, if that is the case, #include that file into your main PRG, or, since I don't see any advantage to doing that, just hardcode the class name and library in the NewObject() line.