How to protect a directory

I'm trying hardly to protect securely a directory.
I'm wondering if I can set some values in the registry to protect it. For instance, assigning a CLSID to my folder, then a develop a program that recognize this CLSID, and only this program can access the folder, or assigning this folder to another directory, Control Panel maybe.
I tried to do it by adding ".{Control Panel's CLSID)".
By clicking in this folder, the Control Panel is shown, instead of my directory contents, but if you go to MS-DOS, you can access this folder quickly ?
Can anybody help me ?

Thanks ...

[620 byte] By [PedroErnesto] at [2007-12-28]