[galaxy-dev] the value of configfile tag

Hi, I have an executable tool that input parameter is an xml string (e.g. run.sh <exam>name</exam>), so how should I set the configfile tag('<configfile><exam>name</exam></configfile>' is not right) if the tool is called by using a tmp-file in command tag (i.e. run.sh $tmp-file) ? thanks welkin