Is it possible to use a parameter from a vs studio project in a c# code

Question

I wanted to know if it is possible to use a int parameter from a vs studio project in my c# code.

Here's some screenshot to make this clearer:

I would like to use "periodeconges" from the xml, so I can modify only the xml without touching the code to change the value.

Here's the part where I want to call "periodeconges":

It says me that the var doesnt exist in the current context.Is there any way to access to the var from the xml ?

Thanks a lot.