how to insert job parameter in new xml stage

[sunnymdatastage]

I have a scenario where I am generating an xml as output and have input columns coming from the transfomer. At this time, I am using the new xml stage (green and silver symbol). I would like to know as how can I insert a job parameter listed in the job properties to a header attribute of the xml.

Right now when i am trying to insert a job parameter it allows me to enter a string but does not allow me to insert a parameter listed under job properties. Will I be able to insert a parameter from job properties?