How to insert an existing macro into "Additional Include Directories"?

Hi Gurus,

I am a C++ programmer using VS 2005. I encountered a strange proplem
described as follows.

In the project's Property Pages, I can insert an existing macro such as
$(SolutionDir) into (Linker -- Input -- Additional Dependencies) by
following the steps below:

1) Select the item "Additional Dependencies", and a browsing button
shows at the right end.

2) Click the browsing button, and a dialog pops up.

3) Click the button "Macro>>" shown at the lower right, and the dialog
is expended. In the expanded dialog, there are a macro list and a new
button "Insert".

4) If I double-click any item in the macro list, or select an item and
press the button "Insert", the corresponding macro name will be added
into the edit box.

I think this is a very convenient feature. However, I find this feature
is not available in (C/C++ -- General -- Additional Include
Directories). I cannot insert a macro by double-clicking, what is more
strange, there should be no the button "Insert"! Why??? Who can tell
me?

I hope someone can give me some tips. Any help will be highly
appreciated. Thanks in advance.

.