If you're so concerned about the complexity the config file, why don't you write an interactive configuration utility?

Back to the matter immedately at hand...

You keep talking about the config file, while you should be talking about the module that reads the config file and the program that uses the module. If you used the code I posted earlier in this thread, you could write your config file as:

[path]
root    = C:\test
code    = %root%\code1
include = %root%\include
lib     = %root%\lib
[download]

instead of

[path]
root    = C:\test
code    = C:\test\code1
include = C:\test\include
lib     = C:\test\lib
[download]

It doesn't get any simpler (from the config file's perspective). What else do you want?