Send pending order based on opening price of the day

I need a script to automate something i do everyday:

A.     The trading strategy is based on the opening price:

B.     Each morning i’ll decide either to sell or buy ( i control this in excel)

the input  should be like this:

C.     Its just one order and it must be activated at the moment there is an opening price.

Example market opens at 65.100

buy: open - delta

sell: open + delta