Routing on IOT Edge

Hi, I have a problem that I have been dealing with for quite some time. Trying to put a "where" in a routing for AZIOT edge hub. have tested this which works. FROM /messages/* WHERE $connectionModuleId = 'noded' INTO BrokeredEndpoint("/modules/testjob/inputs/edgehub") . But what I want to do is a "where" against appProperties. I have tried every conceivable "syntax" for this?? Inserts an example message. 

{ 
  "message": { 
    "systemProperties": { 
      "contentType": "application/json", 
      "contentEncoding": "UTF-8", 
      "iothub-message-source": "deviceMessages", 
      "iothub-enqueuedtime": "2017-05-08T18:55:31.8514657Z" 
    }, 
    "appProperties": { 
      "processingPath": "{cold | warm | hot}", 
      "verbose": "{true, false}", 
      "severity": 1-5, 
      "testDevice": "{true | false}" 
    }, 
    "body": "{\"Weather\":{\"Temperature\":50}}" 
  } 
}

Thanks for any help I can get. Can't find any documentation for this?