How to inject a variable into the JSONPATH expression in the "Validation" area ?

Hi
In the validation section of one of my request, I want to check if the value of this JSONPATH node
$.[?(@.id==${mdecin.id})].acquittee
is equal to false where ${mdecin.id} is a variable defined in a variable's file. When I run my scenario Neoload trows me an error, but when I replace the variable ${mdecin.id} with its value (ex: 10101), the assertion is OK , it's like if Neoload did not inject the value of the variable in the JSONPATH expression. Any idea to face this please.
By the way the JSONPATH expression work perfectly in other platforms.