OS-independent includes of other directory files

Say I have a project file structure like so:

Root:
-----Folder1:
----------Foo.ipf
-----Folder2:
----------Bar.ipf

Is there a way to include bar from foo in an OS-independent way? On a Mac, I can use:

     #include "..\Folder2\Bar"


But this does not work on windows. Trying to use syntax windows likes (below) doesn't seem to work on a Mac:

     #include ":..:Folder2:Bar"


I've looked at the relevant help file (see http://www.igorexchange.com/node/6024 or just DisplayHelpTopic "The Include Statement"), but I can't seem to find anything on this.

Thanks in advance!
After a little more digging (Igor Help Browser --> Search Igor Files for string "::"), I found that the syntax

#include "::Folder2:Bar"

Worked on both Mac and Windows, *after* I updated the Windows Igor version from 6.1.2.1 to 6.3.7.2.

So... sorry for the spam! Hope this helps someone else