[wix-users] How to set default Directory value?

[Souren]

I wanted to have a default value for Directory, so every time user run
setup, same default value will apear as Directory, but in case user
customize the folder then component to be installed in new folder.

So I used:

<SetDirectory Id="DDD_FOLDER" Value="C:\DDD"/>

Now everything works as expected, except that I in later operations where I
use "DDD_FOLDER" (for example set registry key value), it always points to
"C:\DDD", even if user customized directory.

How to get the customized value of directory? Or if that won't play nice
with SetDirectory, how else can I set default(not fixed) value for
Directory?

Thanks