Question Variable in metadata

Hi,
I want to use the value of a variable 'Principale' in my metadata file, but unfortunately I can't get it's value and I got the error below when I consult the data.
Is my syntax correct?

Hi,
Variables are evaluated (or substituted) at execution time by the Runtime, not when consulting / reversing with the Designer.
A good practice is to have a Configuration which uses no variables, for reversing / consulting data.
I hope this helps

Hi,
Yes, It helps.
In fact, I used this variable so that I can change the root of my path according to the environment I'm using: Windows or Unix;
when I change the value of the variable to => /root/Track and Trace/ it didn't recognise it and gave me the error => C:\root\Track and Trace\DHL\To_Treat not found.
How can I solve this problem?
Tank you.

Variables cannot be evaluated from the Designer.
A solution is to create a Configuration without variables as said above, dedicated to your Designer operations (consult data, reverse...).