[amibroker] buy and sell stoploss

[irap1981]

dear all members,
i want to right one indicater which plot on chart, for
buy stoploss (H+L+C)/3)-ATR(1)
sell stoploss(H+L+C)/3)+ATR(1)
this formula i use in metastock from last one now i want use in amibroker.
thank you
with regards
manoj jain