How to point virtual directory Outside domain main folder

[enettech]

Hi,

I want ot creat virtual directory that points outside domain main for multiple clients to share common stuff

i.e

Common Stuff in
---------------------
c:\inetpub\CommonStuff

domain1.com
---------
C:\Inetpub\vhosts\domain1.com

virtual directry
-----------------
CommonStuff points to c:\inetpub\commonStuff

it is not letting me point the folder by using ../../
(tried both ../../CommonStuff and ../.../../CommonStuff)
saying: Physical path is invalid or does not exist

I know this can be done, as plesk-stat is using the same thing.

Plus is there a way to lock it out (like plesk-stat virtual dir) so that custome would not be able to delete it by accident (or change the content of it)

Thanks in advance