It does't work, it doesn't seem to include the test.h file at all... After a little more testing here's what i get:

#define build_root "c:\Test\"

*-- Doen't work #include build_root + "Test.h"
*-- Doen't work  #include "c:\Test\" + "Test.h"

*Works
#include "c:\Test\Test.h"

? MyTEST

>It should work, IMO. Did you try to recompile? If you added the #define MyTest later, it won't work until you recompile (which it should do automatically, BTW, but this doesn't always work).
>
>>Is there any way for this to work ?
>>
>>

>>
>>*-- c:\test\Test.h
>>#define MyTest 1
>>
>>*-- Some program
>>#define build_root "c:\Test\"
>>#include build_root + "Test.h"
>>? MyTEST && Error: Variable MyTest is not found
>>
>>