VWAP of higher time frame candle

Hi to everybody,
I am very new to amibroker , I am trying to find the each 30 minute vwap value which is calculated from 30 nos of one minute candle, Can anybody help me with this coding.
yes it is possible to find vwap of last 30 minutes or one hour but how to pass this value to 30 minutes chart and how to do it for every 30 minutes candle.