Config file provider token replacement

[Sathyakumar Seshachalam]

I have been trying to tokens in my config file replaced with Environment variables within a pipeline job.

Below is my JenkinsFile snippet 

withEnv(['INSTANCE=Something']) {

        configFileProvider(

            [configFile(fileId: 'prescribe', variable: 'DEPLOY_FILE')]) {

            sh "echo $env.INSTANCE" 

            sh "cat ${env.DEPLOY_FILE}"

        }

   }

And my config file provider file, I have tried  possible combinations that came to my mind. Also tried adding a global parameter INSTANCE.

${ENV, var=INSTANCE}

${ENV.INSTANCE}

${env,var=INSTANCE}

${env, var=INSTANCE}

${INSTANCE}

None of the above seems to do the trick. And I have the file without replaced tokens.

Any help will be greatly appreciated