C/S CR1000 precipitation data.

Hi All
At long last I have my Campbell Scientific CR1000 posting data directly to WU with the exception of the precipitation.
Can some kind person shed some light on how the CR1000 can post the hourly rainfall to WU. I have included the latter part of the program which sends the "Public Variables" to WU but the hourly rain data is only available in "Table 1"
Thanks for any help.

    'HTTPGet information to wunderground.com
    http_get_header = ""
    http_get_response = ""
    http_get_uri = "http://weatherstation.wunderground.com/weatherstation/updateweatherstation.php?action=updateraw";
    http_get_uri = http_get_uri & "&ID=" & WUNDERGROUND_ID & "&PASSWORD=" & WUNDERGROUND_PASSWORD
    http_get_uri = http_get_uri & "&dateutc="  & UTCTime
    http_get_uri = http_get_uri & "&winddir=" & Round(WindDir,0)                 'Wind Direction
    http_get_uri = http_get_uri & "&windspeedmph=" & Round(WS_mph,1)             'Wind Speed
    http_get_uri = http_get_uri & "&tempf=" & Round(AirTC * 1.8 + 32,1)          'Air Temp
    http_get_uri = http_get_uri & "&dewptf=" & Round(TdC * 1.8 + 32,1)           'Dew Point
    http_get_uri = http_get_uri & "&humidity=" & Round(RH,0)                     'Humidity
    http_get_uri = http_get_uri & "&solarradiation=" & Round(NR_Wm2,1)             'Solar
    http_get_uri = http_get_uri & "&baromin=" & Round(BP_mbar * 0.02953,1)     'Barometric
    http_get_uri = http_get_uri & "&soiltempf=" & Round(T107_C * 1.8 + 32,1)   'Soil Temp
    http_get_uri = http_get_uri & "&soilmoisture=" & Round(VW,1)                 'Soil Moisture
    http_get_uri = http_get_uri & "&indoortempf=" & Round(PTemp_C * 1.8 + 32,1)  'Panel Temp
    http_get_uri = http_get_uri & "&leafwetness=" & Round(kohms,1)               'Leaf Wetness
    http_get_uri = http_get_uri & "&rainin=" & Round(Rain_mm  / 25.0,1)           'Precipitation
    http_get_uri = http_get_uri & "&softwaretype=cr1000"
    http_get_socket = HTTPGet(http_get_uri, http_get_response, http_get_header)

    'TCPClose(http_get_socket)

  NextScan

EndProg